PDCD1 and non-small cell lung carcinoma: The usage of exogenous immune compounds, such as immune checkpoint inhibitors (ICI), with Cytotoxic T lymphocyte antigen 4 (CTLA4) and programmed cell death 1 (PD-1) being the most commonly targeted molecules, has so far been proven to be an effective option for a number of tumors (NSCLC, bladder cancer, melanoma) and is currently being explored in CC.