In many animal tissues, stem cells continually divide to create new cells that replace old or damaged ones. However, this capacity requires strict regulation, as uncontrolled stem cell proliferation can disrupt tissue homeostasis and contribute to tumorigenesis.

Researchers at the National Institute for Physiological Sciences have identified a previously unknown mechanism that controls stem cell proliferation in the Drosophila intestine. The study reveals that smooth septate junction (sSJ) proteins, known for their role in cell-cell adhesion, also regulate signaling in differentiating intestinal progenitor cells to prevent excessive stem cell growth.