ATP9B and rheumatoid arthritis: In fact, the QTL identified in this study contains genes whose human orthologous had previously been associated with RA in a genome-wide association study (GWAS) [23] such as PTPN2 (protein tyrosine phosphatase, non-receptor type 2, lymphoid), TCF4 (transcription factor 4), ZBTB7C (zinc finger and BTB domain containing 7C), IMPA2 (inositol(myo)-1(or 4)-monophosphatase 2), ATP9B (ATPase class II type 9B or macrophage MHC receptor 1), DYM (dymeclin), CTIF (CBP80/20-dependent translation initiation factor), and CCDC11 (coiled-coil domain containing 11).