Clinical data concluded that the systemic chronic administration of IFN-α or IFN-β accelerate the regression of richly vascularized tumors, e.g., life-threatening hemangiomas of infancy (20), hemangio-endotheliomas (21), hemangiopericytoma (22) and Kaposi’s sarcomas (23). Here, IFNB1 is linked to Kaposi's sarcoma.