ISG15 and melanoma: While no similar correlates have yet been reported for melanoma patient response to targeted inhibitors of regulatory ISGs based on tumor BRAF/PTEN gene expression stratification, at least for ISG15, our screening of a publicly accessible data set failed to reveal any correlation between BRAF mutation or PTEN presence/loss with ISG15 high vs. low expression status in a melanoma cohort (Supplementary Figure 8D).