In an example of successful ISVs, Talimogene laherparepvec (T-VEC), a genetically modified herpes simplex virus that can replicate selectively within tumors and express GM-CSF, is the first intratumoral oncolytic viral therapy approved by the FDA in 2015 for local treatment of unresectable advanced melanoma (Rehman et al., 2016). This evidence concerns the gene CSF2 and melanoma.