Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of GMP2 and Cxcl2_NE, and GO analysis of OMC, showed that the pathways and functions of cell metabolism, rheumatoid arthritis and osteoclast differentiation were significantly upregulated in Pstpip2−/− compared to WT and DKO mice (Fig. S1D,E). This evidence concerns the gene PSTPIP2 and rheumatoid arthritis.