CD4 and arthritic joint disease: Mapping of eQTLs at RA risk loci in lymphocytes of treatment‐naive patients with early arthritis. Expression data from primary peripheral blood lymphocytes were available for a total of 344 genotyped patients with early arthritis; available data on CD4+ lymphocytes were limited to 249 of the patients, data on B lymphocytes were available for 242 of the patients, and paired data were available for 147 of the patients.