We showed positive staining for GFAP-activated astrocytes surrounding melanoma metastases in a cohort of 40 patients diagnosed with MBM bearing WT BRAF (patient-derived 1–5, PD1–PD5, Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.154804DS1). This evidence concerns the gene GFAP and melanoma.