1. Lucas CL, Chandra A, Nejentsev S, Condliffe AM, Okkenhaug K. PI3Kδ and primary immunodeficiencies Nat Rev Immunol. 2016;16(11):702-14. 2. Zhang Q, Ma H, Ma J, Wang D, Zhao Y, Wang T, et al. Clinical and genetic analysis of immunodeficiency‐related diseases associated with PIK3CD mutations. Pediatr Investig. 2018;2(4):257-62. 3. Michalovich D, Nejentsev S. Activated PI3 kinase delta syndrome: from genetics to therapy. Front Immunol. 2018;9:369. 4. Jamee M, Moniri S, Zaki-Dizaji M, Olbrich P, Yazdani R, Jadidi-Niaragh F, et al. Clinical, Immunological, and Genetic Features in Patients with Activated PI3Kδ Syndrome (APDS): a Systematic Review. Clin Rev Allergy Immunol. 2019;10.1007/s12016-019-08738-9. doi:10.1007/s12016-019-08738-9 5. Singh A, Joshi V, Jindal AK, Mathew B, Rawat A. An updated review on activated PI3 kinase delta syndrome (APDS). Genes Dis. 2020;7(1):67-74. 6. Nunes-Santos CJ, Uzel G, Rosenzweig SD. PI3K pathway defects leading to immunodeficiency and immune dysregulation. J Allergy Clin Immunol. 2019;143(5):1676-87. 7. Lucas CL, Zhang Y, Venida A, Wang Y, Hughes J, McElwee J, et al. Heterozygous splice mutation in PIK3R1 causes human immunodeficiency with lymphoproliferation due to dominant activation of PI3K. J Exp Med.2014;211(13):2537-47. 8. Dornan GL, Siempelkamp BD, Jenkins ML, Vadas O, Lucas CL, Burke JE. Conformational disruption of PI3Kδ regulation by immunodeficiency mutations in PIK3CD and PIK3R1. Proc Natl Acad Sci U S A 2017;114(8):1982-7. 9. Petrovski S, Parrott RE, Roberts JL, Huang H, Yang J, Gorentla B, et al. Dominant Splice Site Mutations in PIK3R1 Cause Hyper IgM Syndrome, Lymphadenopathy and Short Stature J Clin Immunol. 2016;36(5):462-71. 10. Elkaim E, Neven B, Bruneau J, Mitsui-Sekinaka K, Stanislas A, Heurtier L, et al. Clinical and immunologic phenotype associated with activated phosphoinositide 3-kinase δ syndrome 2: A cohort study. J Allergy Clin Immunol. 2016;138(1):210-8.e9. 11. Condliffe AM, Chandra A. Respiratory Manifestations of the Activated Phosphoinositide 3-Kinase Delta Syndrome. Front Immunol. 2018;9:338. 12. Coulter TI, Chandra A, Bacon CM, Babar J, Curtis J, Screaton N, et al. Clinical spectrum and features of activated phosphoinositide 3-kinase δ syndrome: A large patient cohort study. J Allergy Clin Immunol. 2017;139(2):597-606.e4. 13. Crank MC, Grossman JK, Moir S, Pittaluga S, Buckner CM, Kardava L, et al. Mutations in PIK3CD can cause hyper IgM syndrome (HIGM) associated with increased cancer susceptibility. J Clin Immunol. 2014;34(3):272-6. 14. Angulo I, Vadas O, Garçon F, Banham-Hall E, Plagnol V, Leahy TR, et al. Phosphoinositide 3-kinase δ gene mutation predisposes to respiratory infection and airway damage. Science (New York, NY). 2013;342(6160):866-71. 15. Ewertowska M, Grześk E, Urbańczyk A, Dąbrowska A, Bąbol-Pokora K, Łęcka M, et al. Activated phosphoinositide 3-kinase delta syndrome 1 and 2 (APDS 1 and APDS 2): similarities and differences based on clinical presentation in two boys. Allergy Asthma Clin Immunol. 2020;16:22. 16. Lougaris V, Baronio M, Moratto D, Tampella G, Gazzurelli L, Facchetti M, et al. A novel monoallelic gain of function mutation in p110δ causing atypical activated phosphoinositide 3-kinase δ syndrome (APDS-1). Clin Immunol. 2019;200:31-4. 17. Lucas CL, Kuehn HS, Zhao F, Niemela JE, Deenick EK, Palendira U, et al. Dominant-activating germline mutations in the gene encoding the PI(3)K catalytic subunit p110δ result in T cell senescence and human immunodeficiency. Nat Immunol. 2014;15(1):88-97. 18. Okkenhaug K, Vanhaesebroeck B. PI3K in lymphocyte development, differentiation and activation. Nat Rev Immunol. 2003;3(4):317-30. 19. Preite S, Gomez-Rodriguez J, Cannons JL, Schwartzberg PL. T and B-cell signaling in activated PI3K delta syndrome: From immunodeficiency to autoimmunity. Immunol Rev. 2019;291(1):154-73. 20. Stokes CA, Condliffe AM. Phosphoinositide 3-kinase δ (PI3Kδ) in respiratory disease. Biochem Soc Trans. 2018;46(2):361-9. 21. Magis-Escurra C, Reijers MH. Bronchiectasis. BMJ clinical evidence. BMJ Clin Evid. 2015;2015. 22. Maccari ME, Abolhassani H, Aghamohammadi A, Aiuti A, Aleinikova O, Bangs C, et al. Disease Evolution and Response to Rapamycin in Activated Phosphoinositide 3-Kinase δ Syndrome: The European Society for Immunodeficiencies-Activated Phosphoinositide 3-Kinase δ Syndrome Registry. Front Immunol. 2018;9:543. 23. Jamee M, Moniri S, Zaki-Dizaji M, Olbrich P, Yazdani R, Jadidi-Niaragh F, et al. Clinical, immunological, and genetic features in patients with activated PI3Kδ syndrome (APDS): a systematic review. Clin Rev Allergy Immunol. 2019:1-11. 24. Martínez-Saavedra MT, García-Gomez S, Domínguez Acosta A, Mendoza Quintana JJ, Páez JP, García-Reino EJ, et al. Gain-of-function mutation in PIK3R1 in a patient with anarrow clinical phenotype of respiratory infections. Clin Immunol. 2016;173:117-120. 25. Asano T, Okada S, Tsumura M, Yeh TW, Mitsui-Sekinaka K, Tsujita Y, et al. Enhanced AKT Phosphorylation of Circulating B Cells in Patients With Activated PI3Kδ Syndrome. Front Immunol. 2018;9:568. 26. Lucas CL, Chandra A, Nejentsev S, Condliffe AM, Okkenhaug K. PI3Kδ and primary immunodeficiencies. Nat Rev Immunol. 2016;16(11):702-14. 27. Swan DJ, Aschenbrenner D, Lamb CA, Chakraborty K, Clark J, Pandey S, et al. Immunodeficiency, autoimmune thrombocytopenia and enterocolitis caused by autosomal recessive deficiency of PIK3CD-encoded phosphoinositide 3-kinase δ. Haematologica. 2019;104(10):e483-e6. 28. Preite S, Cannons JL, Radtke AJ, Vujkovic-Cvijin I, Gomez-Rodriguez J, Volpi S. Hyperactivated PI3Kδ promotes self and commensal reactivity at the expense of optimal humoral immunity Nat Immunol. 2018;19(9):986-1000. 29. Elgizouli M, Lowe DM, Speckmann C, Schubert D, Hülsdünker J, Eskandarian Z, et al. Activating PI3Kδ mutations in a cohort of 669 patients with primary immunodeficiency. Clin Exp Immunol. 2016;183(2):221-9. 30. Cohen JI. Herpesviruses in the Activated Phosphatidylinositol-3-Kinase-δ Syndrome. Front Immunol. 2018;9:237. 31. Seidel MG. Autoimmune and other cytopenias in primary immunodeficiencies: pathomechanisms, novel differential diagnoses, and treatment. Blood. 2014;124(15):2337-44. 32. Lucas M, Hugh-Jones K, Welby A, Misbah S, Spaeth P, Chapel H. Immunomodulatory therapy to achieve maximum efficacy: doses, monitoring, compliance, and self-infusion at home. J Clin Immunol. 2010;30 Suppl 1:S84-9. 33. Edgar JDM, Richter AG, Huissoon AP, Kumararatne DS, Baxendale HE, Bethune CA, et al. Prescribing Immunoglobulin Replacement Therapy for Patients with Non-classical and Secondary Antibody Deficiency: an Analysis of the Practice of Clinical Immunologists in the UK and Republic of Ireland. J Clin Immunol. 2018;38(2):204-13. 34. Berger M, Jolles S, Orange JS, Sleasman JW. Bioavailability of IgG administered by the subcutaneous route. J Clin Immunol. 2013;33(5):984-90. 35. Kracker S, Curtis J, Ibrahim MA, Sediva A, Salisbury J, Campr V, et al. Occurrence of B-cell lymphomas in patients with activated phosphoinositide 3-kinase δ syndrome. J Allergy Clin Immunol. 2014;134(1):233-6. 36. Kannan JA, Dávila-Saldaña BJ, Zhang K, Filipovich AH, Kucuk ZY. Activated phosphoinositide 3-kinase δ syndrome in a patient with a former diagnosis of common variable immune deficiency, bronchiectasis, and lymphoproliferative disease. Ann Allergy Asthma Immunol . 2015;115(5):452-4. 37. Nademi Z, Slatter MA, Dvorak CC, Neven B, Fischer A, Suarez F, et al. Hematopoietic stem cell transplant in patients with activated PI3K delta syndrome. J Allergy Clin Immunol. 2017;139(3):1046-9. 38. Okano T, Imai K, Tsujita Y, Mitsuiki N, Yoshida K, Kamae C, et al. Hematopoietic stem cell transplantation for progressive combined immunodeficiency and lymphoproliferation in patients with activated phosphatidylinositol-3-OH kinase δ syndrome type 1. J Allergy Clin Immunol. 2019;143(1):266-75. 39. Quinti I, Soresina A, Spadaro G, Martino S, Donnanno S, Agostini C, et al. Long-term follow-up and outcome of a large cohort of patients with common variable immunodeficiency. J Clin Immunol. 2007;27(3):308-16. 40. Jung S, Gámez-Díaz L, Proietti M, Grimbacher B. “Immune TOR-opathies,” a Novel Disease Entity in Clinical Immunology. Front Immunol. 2018;9:966.