We determined by quantitative analysis that BLK RNA expression is not significantly different in human peripheral blood CD19+ B-cells of healthy individuals and our CVID patients carrying L3P-BLK gene variant (Figure 2A), but is absent in monocyte-derived dendritic cells (DCs) and human CD4+ T-cells in circulation (our data not shown). This evidence concerns the gene CD4 and common variable immunodeficiency.