CDKN1C and adenoma: In contrast to the complete absence of stem cell activity for p57+ normal crypt cells in the steady-state (Fig. 4), however, we observed lineage tracing events for p57+ adenoma cells (Fig. 8f), with the width of segments ranging from 50 to 500 μm and at least one tracing event being apparent in ~17% of microscopically visible tumors (mean ± SEM = 17.2 ± 1.01%, n = 3 mice).