These results are consistent with a previous study demonstrating that IL-21 promotes Rorc mRNA expression in both healthy control and RA PBMC, although they did not compare the expression of Rorc mRNA between the healthy control and RA patients 52; it also supports the notion that there is a limited role for the master regulator RORγt in initiating the establishment of active enhancer networks in Th17 lineages 53. Here, IL21 is linked to rheumatoid arthritis.