MCC is a rare (incidence of 0.44 per 100,000), highly aggressive form of skin cancer. Indeed, MCC has a dramatically higher mortality rate after initial diagnosis than malignant melanoma (37 vs. 15 percent). Almost half of the patients with completely resected MCC will relapse with loco-regional or distant metastases within the first two years after initial diagnosis of this highly immunogenic cancer. This high mortality rate is largely due to the fact that to date there is no established adjuvant therapy for completely resected MCC, and none of the until recently available therapeutic interventions was able to improve overall survival of patients suffering from metastatic disease. Consequently, new therapeutic strategies both for the adjuvant as well as the palliative setting are needed.