CIITA and neoplasm: These results were at variance with respect to those obtained by the group of Ostrand-Rosenberg and colleagues, who studied the function of MHC class II expression in tumors by focusing however mostly on a single tumor model, the H-2K SaI sarcoma, and on MHC class II alpha-beta transfected genes, in absence of invariant chain, reaching the conclusion that class II-transfected cells could be better rejected as compared to CIITA-transfected cells (34, 35).