Consequently, immune modulation is a promising therapeutic option for MCC patients, which is currently tested in several clinical trials including: autologous MCPyV-specific CD8+ T-cell transfer, checkpoint blocking antibodies, or cytokine-based therapies using tumor stroma-targeting antibody-IL2 fusion proteins and in vivo electroporation of IL-2-coding plasmids (reviewed in ref. 30). Here, IL2 is linked to Merkel cell skin cancer.