Remarkably, in mice in which MOC2-CIITA tumors were delayed in their growth in vivo, the expression of MHC-II molecules was significantly reduced compared to that of MOC2-CIITA cells the day of injection, as demonstrated by FACS analysis of tumor cells isolated from MOC2-CIITA tumors explanted at 4 weeks after injection (Figure 6). Here, CIITA is linked to neoplasm.