MCAM and neoplasm: It is intriguing to find that the tumors derived from the METCAM clone 2D were barely visible with the naked eye, but visible under microscope in the tumor sections (Fig. b, panels a and b in H&E stain and panels e and f in IHC), which appeared to be confined to small regions, whereas tumors derived from the control (vector) 3D were not confined (Fig. 4b, panels c and d in H&E stain and panels g and h in IHC).