All the 9 hub genes were up-regulated in patients with KD except for CD8A. The results of GO functional enrichment indicated that these 9 genes were enriched mainly in positive regulation of defense response, immune response-regulating signaling pathway, positive regulation of interleukin-6 production and cell activation, as well as two KEGG that are Osteoclast differentiation and Yersinia infection. The gene discussed is CD8A; the disease is Yersinia infectious disease.