In a study by Witalisz-Siepracka et al., deletion of CDK8 enhanced the NK-cell cytotoxicity through releasing more perforin in vitro, and enhanced cytotoxicity was apparent in three in vivo models: B16F10 melanoma, v-abl+ lymphoma, and an oncogene-driven leukemia [54]. This evidence concerns the gene PRF1 and melanoma.