The results of KEGG showed that the DEGs mainly enrich in Antigen processing and presentation, Coronavirus disease—COVID‐19, Rheumatoid arthritis, Leishmaniasis, Phagosome, Intestinal immune network for IgA production, Tuberculosis, Asthma, Th17 cell differentiation, HIF − 1 signalling pathway, Haematopoietic cell lineage, Graft−versus−host disease, Type I diabetes mellitus, Influenza A, Inflammatory bowel disease, Allograft rejection, Glycolysis/Gluconeogenesis, Ribosome, Staphylococcus aureus infection and Th1 and Th2 cell differentiation. The gene discussed is SETD2; the disease is COVID-19.