Also enriched in NR tumors were the inflammatory cytokine IL1B, and chemokine CXCL6 which has been implicated in melanoma growth and metastasis.46 There was no obvious correlation between receipt of prior immunotherapy and response or expression level of type I IFN or IFNAR1/2-related genes, despite the majority of immunotherapy pre-treated patients (n = 5, 71%) having received checkpoint blockade agents for the treatment of metastatic disease (Fig. 7b). Here, CXCL6 is linked to melanoma.