MKI67 and neoplasm: Frequently, pathologists are interested in identifying a nuclei subset from a particular anatomical region (e.g., tumor nuclei in lamina propria in T1 bladder cancer [43]; the ratio between Ki67-positive tumor nuclei and total tumor nuclei in neuroendocrine tumors of the breast or pancreas [44,45]; and centroblasts; presence in the follicles in follicular lymphoma, etc.).