STK26 and neoplasm: The results of tdTomato lineage tracing showed that MST4+ cells were mainly found at the bottom of the crypts for normal part of mouse colon (Figure 8c). However in the tumor tissue, MST4+ cells were markedly increased spreading all over the tumor tissue with significantly elevated levels of β‐catenin; staining signals for Ki67 were readily detected in these cells (Figure 8c).