CD274 and adenocarcinoma: Enwere et al. found that PD-L1 was positive in 88% of their patient samples that comprised 106 SCCs and 14 adenocarcinomas [11]; moreover, Heeren et al. reported that PD-L1 was positive in 54% (83/154) of the SCCs they investigated, which was a significantly higher proportion than its positivity rate in adenocarcinomas (14%; 7/49) [10].