CDKN1A and rheumatoid arthritis: qPCR confirmed upregulation of CSF2 (4.1 ± 0.8 fold versus untreated activated control, p = 0.022), IL1A (4.3 ± 0.8 fold, p = 0.02), TGFA (5.2 ± 1.1 fold, p = 0.015) and CDKN1A (3.8 ± 0.4 fold, p = 0.008) in RA-FLS by MTX (Fig. 2E).