CTLA4 and breast cancer: There are several ongoing clinical trials using anti-PD-1 pembrolizumab (Keytruda) [39], anti-PD-L1 avelumab (Bavencio), anti-PD-L1/TGF-β trap fusion M7824, anti-CTLA-4 tremelimumab, and anti-PD-1 durvalamab (Imfinzi) as adjuvants to various BC vaccines (see Table 2).