MKI67 and neoplasm: Next, we further examined pathological progression using hematoxylin and eosin (H&E) staining of prostates of PtenPC−/− mice and found that OTUD6A deletion reduced the rate of tumor formation and impaired the progression of Pten-null prostate tumors, coupled with reduced levels of the proliferation marker Ki67 (Fig. 3c and Supplementary Fig. 3b, c).