Talimogene laherparepvec (T-VEC) is a genetically modified herpes simplex type 1 virus that selectively infects and replicates tumor cells, whilst expressing granulocyte macrophage colony-stimulating factor (GM-CSF) which, in turn, stimulates antigen-presenting cells to initiate and propagate lymphocyte activation. Here, CSF2 is linked to neoplasm.