Specifically with respect to X chromatin inactivation, TLR7 has been found to bypass X chromosome inactivation in pDCs, B cells and monocytes in SLE patients or men with Klinefelter syndrome, resulting in increased TLR7 expression and TLR7 ligand responsiveness in B cells, driving them to differentiate into antibody secreting cells [61]. Here, TLR7 is linked to Klinefelter syndrome.