AR and prostate neoplasm: Further pathological evaluation indicated that knockin of Klf5KR resulted in more proliferative cells in prostate tumors, as suggested by both the mitotic images and frequency of Ki67+ cells (Figure 2, C–E), but did not significantly altered the expression patterns of epithelial markers, such as Ar, Ck5, and Ck8 (Supplemental Figure 1C).