DHCR7 and rheumatoid arthritis: Similarly, Yarwood et al. investigated the effect of vitamin D on treatment response, testing six vitamin D-associated SNPs (rs10741657, rs3829251, rs1790349, rs12785878, rs1155563, and rs7041 on genes GC, DHCR7/NADSYN1, and CYP2R1) for association with response to anti-TNF therapy, in 1396 RA patients from Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate (BRAGGSS).