Several immune-related pathways were enriched in KEGG pathway analysis, including amebic protozoa, hematopoietic cell line, allotransplantation rejection, rheumatoid arthritis, asthma, African trypanosomiasis, autoimmune thyroid disease, leishmaniasis, primary immunodeficiency, staphylococcal infection, measles, B cell receptor signaling pathway, natural killer cell mediated cytotoxicity, viral myocardium, FcγR mediated phagocytosis, FcεRI signaling pathway, phospholipase D signaling pathway, and the NF-κB signaling pathway (Fig. 6, Table 2 and Additional file Table S5). Here, FCGR2A is linked to rheumatoid arthritis.