Single-cell profiling of PBMCS reveals an immune signature of irAEs in anti-PD-1-treated acral melanoma patients

Our findings propose a model wherein an imbalance in CD8+ T cell differentiation, favoring aggressive cytotoxic effectors over a putative buffering transitional population, underpins irAEs pathogenesis in acral melanoma patients receiving anti-PD-1 therapy. The transitional-to-cytotoxic CD8+ T cell ratio emerges as an exploratory candidate biomarker for irAEs risk, warranting validation in larger prospective cohorts.