Merkel cell carcinoma (MCC) is a rare, highly aggressive neuroendocrine skin cancer. More than 80% of MCC have Merkel cell polyomavirus (MCPyV) clonally integrated into the human genome (VP-MCC) while the remaining 20% are virus negative (VN-MCC) but linked with chronic exposure to UV sunlight. MCC is particularly associated with immune suppression with 8-48 folds increase in incidence in immunosuppressive ...