CD274 and mucinous adenocarcinoma: Specifically, PD-L1 positivity in tumor cell membrane was detected in 11 of 25 (44.0%) adenoid cystic carcinoma patients, 7 of 11 (63.6%) mucoepidermoid carcinoma patients, 5 of 9 (55.6%) adenocarcinoma patients, and 1 of 2 (50.0%) mucinous adenocarcinoma patients.