The predictive value of TMB to anti-PD1/PD-L1 and anti-CTLA4 therapies has been shown across multiple cancer types, including melanoma and non-small cell lung cancer (NSCLC) [24,25], which led to the US Food and Drug Administration (FDA) approval of TMB-high as a tumor agnostic predictive biomarker for pembrolizumab in 2020. This evidence concerns the gene PDCD1 and cancer.