URAD and rheumatoid arthritis: In the present study, pyrosequencing-based technical validation of the CpG sites selected confirmed several DMPs to be associated both with the risk of RA (cg21950155 [gene PRHOXNB] and cg08161306 [gene TBC1D22A]) and with the severity of RA (cg15971518 [gene PRG2] and cg19052272 [gene ALLC]).