Since ST binds and potentiates MYCL function through the ST-MYCL-EP400 complex (15), we suspected that viral antigen inactivation might also upregulate class I. To explore this, we transduced another established MCPyV+ MCC line, WaGa, with an shRNA targeting shared exons of ST and LT, leading to inactivation of both viral antigens. This evidence concerns the gene MYCL and Merkel cell skin cancer.