IL2RB and rheumatoid arthritis: More recently, large-scale whole-genomic association (WGA) studies have suggested a number of novel RA susceptibility loci including variation close to both the alpha and beta chains of the IL2 receptor (IL2RA and IL2RB), a single-nucleotide polymorphism (SNP) in linkage disequilibrium with variation at the TRAF1-C5 locus, two independent signals on chromosome 6q23, and a female-specific effect on chromosome 7q32 [6-8].