TNFSF13B and familial dilated cardiomyopathy: High levels of B-cell activating factor BAFF (TNFSF13B) and TNF receptor superfamily member 13B (TNFRSF13B), both involved in B-cell homeostasis and regulation, underline the hypothesized role of B-cell regulation in DCM [57], but have to be studied at the immune cell level in more detail.