Similarly, in female melanoma, the estrogen-ERα signal drives macrophages to polarize towards the M2 phenotype, inhibits the function of CD8+ T cells, promotes melanoma progression and induces immune checkpoint blockade (ICB) resistance, while the antagonist of ER (Fulvestrant) can reverse the immunosuppressive microenvironment and restore T cell function (63). Here, ESR1 is linked to melanoma.