CDKL2 and rheumatoid arthritis: Further, we explored GO enrichment analysis of the genes and found that the most significant terms in BP were “immune response,” “signal transduction,” and “protein homooligomerization.” The most highly enriched terms from KEGG analysis were “Rheumatoid arthritis.” Finally, we observed the methylation site of CDKL2 in the MethSurv network, wherein we found that cg00977384, cg14988503, cg05426966, cg14263942, cg10344081, cg03757145, cg20463808, cg24432073, and cg05982271 were significantly related to prognosis.