PDCD1 and neoplasm: Subsequently, four antibodies (pembrolizumab, nivolumab, cemiplimab, and dostarlimab) targeting the co-inhibitory programmed cell death protein 1 (PD-1) and three antibodies (atezolizumab, durvalumab, and avelumab) directed against the programmed cell death ligand 1 (PD-L1) were demonstrated to effectively improve survival in several malignancies (134, 135) which led to the FDA-approval for treatment of 19 different cancer types and two tissue-agnostic conditions [that is a tumor with a specific genetic alteration regardless of the cancer type and location (136)].