MKI67 and neoplasm: Small-sized uniform tumor cells with a high nuclear cytoplasmic ratio grow in a solid or nested pattern (Figures 4A, 5A, 6A), and immunohistochemical analysis showed high Ki-67 labeling index values (74% in A99, 58% in TYUC-1 and 74% in TCC-NECT-2) (Figures 4B, 5B, 6B).