CD4 and rheumatoid arthritis: Similarly, the minor allele of the IL-4R SNP (rs1805010), which confers impaired IL-4 signaling and has been associated with an aggressive destructive course of rheumatoid arthritis (RA), contributes to increased TH17 cell frequency, enhanced clinical activity, and accelerated radiographic progression in RA by rendering CD4 T cells from RA [32].