In the same age range two CVID patients (V11, V15), segregated according to their relative TCM CD4+ expansion, maintaining normal TN CD8+ frequencies: V15 carried a Cytotoxic T-Lymphocyte-Associated protein 4 deficiency (CTLA4) while patient V11 is still under investigation (Figure 4B). This evidence concerns the gene CTLA4 and common variable immunodeficiency.