CIITA and neoplasm: Indeed, when applied to in vivo experimental animal models of highly tumorogenic MHC-II-negative cancer cells we could demonstrate that CIITA-induced MHC-II expression was instrumental in rendering these tumor cells immunogenic and rejectable, or strongly retarded in their growth, when injected in syngeneic immunocompetent recipients including mammary, colon and renal carcinomas, as well as sarcomas [42,43].