Through our integrated clinical-biomarker–immunologic analyses derived from a diverse, pan-tumor cohort, we found that early increases in Th17 (IL-6, IL-17f), type 2 (IL-5, IL-13, IL-25), and type 1 (TNF-α) cytokines were associated with the development of grade ≥ 2 irAEs. This evidence concerns the gene IL13 and neoplasm.