CD274 and neoplasm: We tested several β-lactam antibiotics for tumor PDL1 depletion, including penicillin G and other β-lactams in the cephalosporin and related antibiotic classes, such as the first-generation cephalosporin cefazolin, the carbapenem meropenem, the third-generation cephalosporin ceftriaxone, and the fourth-generation cephalosporin ceftazidime.