CD274 and COVID-19: Besides, investigation of the KEGG pathway analysis primarily suggested that these DRGs were involved in virus-related diseases, including Influenza A, Measles, Epstein-Barr virus infection, and Coronavirus disease - COVID-19, and inflammatory and immune-related signaling pathways such as NOD-like receptor signaling pathway, NF-kB signaling pathway, IL-17 signaling pathway, TNF signaling pathway, PD-L1 expression, and PD-1 checkpoint pathway, and B cell receptor signaling pathway (Fig. 3D).