CTLA4 and renal cell carcinoma: Whereas in the retrospective study of Sen et al. involving 172 patients with RCC, NSCLC, melanoma, sarcoma, and gastrointestinal stromal tumors, antibiotics were applied to patients during (n = 54), 30 (n = 19) or 60 d (n = 14) prior to PD-1 and/or CTLA-4 blockade.75 Contrastingly, neither PFS nor overall survival showed any difference between antibiotic-treated and untreated patients at all time points, except that a decrease in overall survival was observed in patients with the use of antibiotics 30 d before treatment.