TAM can be polarised upon IFNγ stimulation into a M1 phenotype, which exhibit enhanced anti-tumorigenic properties; or into a M2 phenotype upon IL-4 stimulation, which exhibit pro-tumorigenic activities.15 Immunohistochemistry on primary melanoma biopsies revealed an increase in TAM infiltration with melanoma progression,16 which also correlated with increased melanoma invasiveness and metastasis.17 Interestingly, from a small cohort of metastatic melanoma patients treated with BRAFi, higher numbers of TAM before treatment correlated with shortened progression-free survival.18 The gene discussed is IL4; the disease is melanoma.