PDCD1 and neoplasm: In the KEYNOTE-158 study of 10 tumor types leading to pan-solid tumor approval of pembrolizumab (anti-PD-1) monotherapy in second-line or greater line TMB-H patients, while a higher objective response rate was observed in those TMB-H (29%) versus TMB-Low (-L; 6%), numerically more objective responses were observed in those TMB-L (43/688) versus TMB-H (30/102; ref. 4), consistent with similar studies indicating that TMB-H alone misses most anti-PD(L)1 therapy-responsive patients (5).