MKI67 and neoplasm: For decades, the Ki‐67 protein has served as a widely employed marker for assessing the proliferation of human tumor cells. Ki‐67 has roles in both interphase and mitotic cells, and its cellular distribution dramatically changes during cell cycle progression. For example, during interphase, Ki‐67 is required for normal cellular distribution of heterochromatin antigens and for the nucleolar association of heterochromatin [33].