In addition, mutations in similar genes, like TNFRSF13 (TACI), TNFRSF13C (BAFF-R), TNFRSF12 (TWEAK), and TNFRSF7 (CD27) were found in individuals with selective IgA deficiency or CVID (49, 50). Here, TNFRSF13C is linked to selective IgA deficiency disease.