The most prominent example of the clinical translation of oncolytic viruses is talimogene laherparepvec (T-VEC, trade name ImlygicTM), a genetically modified herpes simplex virus type I. In addition to gene knockouts for enhanced tumor specificity and immunogenicity [168], T-VEC encodes the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) for increased infiltration and activation of myeloid cells to support antitumor immunity [169]. The gene discussed is CSF2; the disease is neoplasm.