Recently, it is underscored the importance of the immune response in MCC; for example, (according to [18]) CD8+ lymphocytes were found to significantly influence overall survival and disease-specific survival; furthermore, it was demonstrated that MCPyV presence serves as a strong prognostic factor, triggering a host immune response involving various lymphocyte subclasses such as CD3, CD8, FoxP3, and PD-L1 positive cells in MCC. Here, FOXP3 is linked to Merkel cell skin cancer.