CD274 and cancer: Go enrichment analysis (Figure 4A) showed that the biological functions of hub genes were focal adhesion, cell–substrate junction, cytosolic and ribosome, etc. The KEGG enrichment analysis (Figure 4B) revealed that hub genes had the functional pathways of the ribosome, proteoglycans in cancer, PD-L1 expression, and PD-1 checkpoint pathway in cancer, endometrial cancer, and interestingly, coronavirus disease (COVID-19).