HGF and melanoma: Examination of BRAF-mutant melanoma patients treated with BRAF and/or MEK inhibitors revealed that expression of HGF in tumor-associated stromal cells inversely correlated with response to therapy, and perhaps most importantly, on-treatment biopsies taken 2 weeks after initiation of therapy showed an increase in stromal HGF expression in a subset of patients, suggesting that stromal HGF may contribute to tumor cell persistence early in the course of therapy.