PDCD1 and cancer: Considering that TIDE [56], MSI.Score (microsatellite instability) [87, 88], TMB (tumor mutational burden) [89–92], CD274 [93], CD8 [94], IFNG (IFNγ) [95], T.Clonality [96], B.Clonality [97] and Merck18 (T-cell-inflamed signature) [95] were constructed for the purpose of predicting response to ICB, and the recent FDA approval granting the use of pembrolizumab (PD1 blockade) therapy for solid tumors in adults with high MSI and TMB score [63], the matching efficacy of Overlap36 validates its potential as a novel predictor of cancer response to ICB.