FMR1 and fragile X syndrome: A paper from the same group recently reported evidence of elevated levels of IL-6 and Tenascin C (TNC), a known endogenous ligand of TLR4 that has been shown to induce the expression of pro-inflammatory cytokines such as IL-6 in Fmr1 KO astrocytes, indicating a potential immune mechanism associated with FXS [94].