Thus, reduced counts (vs age-matched HD) of the more advanced stages of maturation of CD5+ CD38+/++ CD21het CD24++ (2.7 vs 5.6 cells/μl, p=0.0004) and CD5+ CD38het CD21+ CD24+ (6.5 vs 17 cells/μl, p<0.0001) immature/transitional B cells was detected in 22% and 37% of CVID patients. The gene discussed is CD38; the disease is common variable immunodeficiency.