Sun et al. (2013) investigated whether PSORS1C1/CDSN was involved in RA and found that the TagSNPs rs3130983, rs3778638, and rs4959053 in the PSORS1C1/CDSN locus were shown to predict susceptibility to RA in two independent RA cohorts. Here, PSORS1C1 is linked to rheumatoid arthritis.