Talimogene laherparepvec (T-VEC; ImlygicTM) is an oncolytic herpes simplex virus that uses GM-CSF expression as an immune enhancer and has gained FDA approval for cancer immunotherapy in 2015 (T-VEC will be covered more in the next section), indicating cytokines can enhance the oncolytic virus-induced immune response against tumors. Here, CSF2 is linked to cancer.