...we found the median TMB score (69.08 vs.14.37) was significantly different between KMT2C/2D MT and WT group (R squared 0.5527, 95% CI -73.8 to -35.63, p<0.0001), and the median OS differed widely (34 vs. 13 months) in KMT2C/2D MT and WT group (HR 0.46, 95% CI 0.24 to 0.88, p<0.05) ; the results supported that mutations in KMT2C/2D was associated with higher TMB and OS with ICI treatment.