TCF21 and rheumatoid arthritis: The KEGG pathway frequency analysis presented that up-regulated gene groups (Tcf21-MP/Control-MP) included cytokine-cytokine receptor interaction, TGF-beta signaling pathway, HIF-1 signaling pathway, PI3K-Akt signaling pathway, renin secretion, rheumatoid arthritis, galactose metabolism, NF-kappa B signaling pathway, tuberculosis, mineral absorption, and malaria (Fig. 3a).