We found across several published ICI-treated patient cohorts (in total, n = 79 dual ICI, n = 134 mono anti-PD-1 and n = 42 mono anti-CTLA-4 ICI-treated patients16–19) that a high baseline IL-17 GES level in melanoma tissue is significantly associated with improved therapy response in dual-ICI-treated but not in mono ICI-treated patients. Here, PDCD1 is linked to melanoma.