CD274 and cancer: Anti-PD-L1 antibodies can be profitably used for the precise delivery of toxic payloads in a wide range of cancers that are positive for PD-L1, because the expression of PD-L1 was found in various solid malignancies, such as squamous cell carcinoma of the head and neck, melanoma and carcinomas of the brain, thyroid, thymus, esophagus, lung, breast, gastrointestinal tract, colorectum, liver, pancreas, kidney, adrenal cortex, bladder, urothelium, ovary, skin and others (Wang et al., 2016).