CD8A and acral lentiginous melanoma: Additionally, AE patients exhibited an elevated proportion of proliferating T cells and enrichment of cell-killing gene pathways.<h4>Discussion</h4>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.