TYK2 and rheumatoid arthritis: On reanalyzing data from association studies on rheumatoid arthritis (RA)30, the variants in the PRKCB and PLD4 loci were found to be associated with RA in East Asians but not in Europeans (CQ-test P = 0.004 and 0.010 for PRKCB and PLD4, respectively), while the variant in TYK2 was found associated in Europeans only (CQ-test P = 0.002; Fig. 3b and c).