Interestingly, recent studies have shown that hormones such as estrogens can modulate the expression of BAFF.53, 54 Additionally, pregnancy hormones have also an impact in circulating B cells, which seems to suggest that the hormone milieu of pregnancy may induce B‐cell lymphopenia, thus the relative availability of BAFF receptors will also be limited, which may lead to an increase in serum BAFF levels. The gene discussed is TNFSF13B; the disease is Decreased total B cell count.