STING1 and Merkel cell skin cancer: By analyzing published RNA-seq data [72], we discovered that while STING is amply expressed in the MCPyV- MCC cell line UISO, STING RNA levels are nearly undetectable in all six classic MCPyV+ MCC cell lines: MKL-1, MKL-2, MS-1, WaGa, PeTa and BroLi (Figure S5A).