MECP2 and systemic lupus erythematosus: Future research should aim to establish whether any of the SLE-associated SNPs in MECP2 has a functional effect and to find evidence of the hypothesized relationship between altered methylation of T-cell genes in SLE and MECP2. In addition, it is even unclear whether the causal polymorphism affects MECP2 because SLE association has also been reported with genetic variants in a neighbour gene, IRAK1, which is a key mediator in the signalling pathways of Toll-like receptors/IL-1R [24].