Reference: Hargreaves, C.E., Salatino, S., Sasson, S.C. et al. Decreased ATM Function Causes Delayed DNA Repair and Apoptosis in Common Variable Immunodeficiency Disorders. J Clin Immunol (2021). https://doi.org/10.1007/s10875-021-01050-2 Bottom line: Decreased pATM promotes DNA repair defects and promotes apoptosis. Complex CVID and Infections CVID have a differential expression of genes TOP3A, XRCC2, and MSH6.