CD274 and cancer: Indeed, the use of antibiotics before anti-PD-1/PD-L1 or anti-CTLA4 antibody monotherapy was associated with negative clinical outcomes in several meta-analyses and prospective studies, regardless of cancer type and geographic region (Lurienne et al. 2020; Wilson et al. 2020; Derosa et al. 2021; Matson et al. 2018).