CSF2 and neoplasm: Preclinical results indicated that incorporation of GM-CSF into the oncolytic virus was important for the systemic antitumor effect of T-VEC since this resulted in increased tumor shrinkage of uninjected tumors in mice.1 In a phase II study in patients with melanoma,9 an ORR of 26 % was reported, with responses frequently observed in uninjected lesions, including visceral lesions.