Recently a randomized, Phase III trial of talimogene laherparepvec in patients (pts) with unresected melanoma with regional or distant metastases (OPTiM) met its primary endpoint, demonstrating a significant improvement in durable response rate (defined as partial or complete responses that were maintained for ≥6 months starting within 12 months) versus GM-CSF alone (16 versus 2%, p < 0.0001) (17). Here, CSF2 is linked to melanoma.