Bomze D, et al. - Postmarketing data of adverse events from the US Food and Drug Administration Adverse Event Reporting System from July 1, 2014, to March 31, 2019, was pooled in order to examine the relationship between immune-related adverse events (irAEs) reported during anti-programmed cell death 1 [PD-1] therapy and tumor mutational burden (TMB) by contrasting large-scale surveillance data of irAEs with the median TMB across various cancer types. A total of 47,304 AEs in 16,397 individuals reported as treated with anti–PD-1 monotherapy for 19 various cancer types were recognized. Provided the results of the analysis, it was revealed that the relationship between irAEs and enhanced response to anti–PD-1 treatment are connected through an underlying neoantigenic potential that originates from a high TMB.