RORC and autoimmune disease: RORs also play important roles in immunity.87 Extensive research has established RORγt, a subtype of RORγ, as a master regulator of Th17 cell differentiation and therefore highly involved in autoimmune diseases.127 In Th17 cells, RORγt is expressed at dramatically higher levels during daytime than at nighttime.128 This diurnal expression pattern in turn up-regulates BMAL1-dependent Rev-erb expression during daytime and conversely represses NFIL3 transcription.