CD40LG and systemic lupus erythematosus: Overexpression of several X-linked genes has been shown to be involved in SLE pathogenesis, such as CD40LG [99], CXCR3 [100], KDM6A [101], CXorf21 [98], MECP2 [102, 103], IRAK1 [75, 103], TLR7(Toll-like receptor 7) [104, 105], GPR173 [106], and PRPS2.