T-VEC, a genetically modified oncolytic virotherapy derived from herpes simplex virus type I (HSV-1) encoding the human granulocyte-macrophage colony-stimulating factor (GM-CSF), is the most recent FDA-approved vaccine for the treatment of unresectable cutaneous, subcutaneous, and recurrent nodal lesions in patients with melanoma following initial surgery. This evidence concerns the gene CSF2 and melanoma.