We provide evidence for an additive negative effect of IL-6, HGF, and MCP-2 on response rate in patients with advanced melanoma receiving either single or combination ICI therapy, with patients with combined elevated (i.e., above the median) levels of the three inflammatory proteins at baseline being three times less likely to respond to therapy than patients with combined low (i.e., below the median) levels. Here, IL6 is linked to melanoma.