CD274 and cancer: Indeed, several works on different human cancers correlated high PD-L1 expression with enhanced epithelial–mesenchymal transition, an initial phase of cancer spread, with cancer cells acquiring specific mesenchymal phenotypes, including morphological changes, expression of mesenchymal surface markers and related transcription factors, also suggesting a crosstalk between PD-L1 expression and chemoresistance [42,43].