LTA and Merkel cell skin cancer: sT is more commonly found than LT antigen in MCPyV-positiveMCC tumors and is present in most MCC tumors.114 In MCC cells, overexpression of LTt does not fully restoregrowth inhibition when MCPyV LTt and sT are removed.106 These findings suggest a critical function for sT in MCPyV-relatedtumor progression.