Accordingly, Cordova et al. (56) confirmed these results using polyclonal γδ T cell lines derived from melanoma; both Vδ1 and Vδ2 T cell lines produced equal amounts of TNF-α and IFN-γ, but while the majority (75%) of Vδ1 T cell lines exerted potent cytotoxic activity against melanoma cell line in vitro, only 25% of the Vδ2 T cell lines showed appreciable lytic activity. This evidence concerns the gene IFNG and melanoma.