In a study by Diogo et al. on the deep exon sequencing of 25 candidate genes from GWAS [44], the authors combined DNA in 10 pools of 50 patients with RA and 13 pools of 50 matched controls (each pool containing the same amount of DNA from each individual), identifying an accumulation of missense variants in the interleukin 2 receptor subunit alpha (IL2RA) and beta (IL2RB) gene, and showing that variants within the protein-coding portion of a subset of biological candidate genes identified by GWAS may contribute to RA risk. Here, IL2RA is linked to rheumatoid arthritis.