<i>Klf5</i>’s hemizygous deletion promotes cell proliferation and induces hyperplasia while its homozygous deletion causes apoptosis in the prostate.

<p>Shown in the upper panels is the IHC staining of Ki67 in 1-year-old dorsal prostates, and the ratio of Ki67-positive cells is significantly higher in the prostate with <i>Klf5</i> hemizygous deletion than those with wildtype <i>Klf5</i> or homozygous deletion of <i>Klf5</i> (upper right panel). The lower panels show apoptotic cells (indicated by arrows) as detected by TUNEL assay in the anterior prostates from 1.5-year-old mice, and the ratio of apoptotic cells in the homozygous deletion group is about double that in the wildtype or hemizygous deletion group (lower right panel). Three mice per genotype were counted.