CD274 and cervical carcinoma: It has been shown that normal cervical epithelium hardly expresses PD-L1; however, most cervical cancer cells display intense PD-L1 expression, being HPV positively correlated with increased levels of PD-L1 (Yang et al., 2013; Dyck and Mills, 2017; Liu et al., 2017; Chen et al., 2021).