CD274 and neoplasm: Correlation analysis between the methylation data of these sites and the protein expression data in the TCPA database showed that the degree of methylation at site cg20469139 was correlated with the levels of two apoptosis-related proteins, PDL-1 (Figure 4D) and caspase-7 (Figure 4E), suggesting that this site may affect the prognosis of patients by regulating tumor cell apoptosis.