Thus, considering PD-L1 as a promising target for breast cancer, we investigated the ability of PD-L1_1, the novel human anti-PD-L1 antibody9 and its high affinity variants (Cembrola et al., Rapid affinity maturation of novel anti-PD-L1 antibodies by a fast drop of the antigen concentration and FACS selection of yeast libraries, submitted for publication, 2019), previously generated in our laboratory, to inhibit PD-L1-positive mammary tumor cell growth. The gene discussed is CD274; the disease is breast cancer.