Although the association between TGF-β and clinical response to immunotherapy is logical, a limitation of the present study is the small number of patients, the lack of a control cohort (i.e., metastatic melanoma patients treated with anti-BRAF agents) and of a comparison between TGF-β peripheral blood and tissue levels, which should be addressed in further studies enrolling a larger patient population. Here, BRAF is linked to metastatic melanoma.