London, United Kingdom - September 09, 2025 A video captured by researchers at King’s College London and the Francis Crick Institute shows a weak epithelial cell generating a lightning-like electrical flash just before being extruded and dying. Epithelial cells, which line all organs, maintain healthy protective layers by removing their weakest, energy-deficient neighbors through a process called extrusion. The video captures the weak cell flashing electrically as it expends its last energy, signaling it for removal. Neighboring cells detect which cell has the lowest energy, then trigger extrusion. The weak cell shrinks and is expelled, maintaining a balanced and tightly packed tissue. Dr. Saranne Mitchell explained, “We see this sodium channel acting as a sensor, exposing cells with the least amount of energy and targeting those cells for death. It’s like an electrical quality-control check, keeping tissues robust and functional.” Professor Jody Rosenblatt added, “By revealing that cells with low energy are targeted for extrusion, our work also adds a new layer into how metabolism can impact many diseases, including cancer and stroke.” The video highlights a previously overlooked role of cellular electricity beyond nerve cells, showing how tissues use this process to maintain health and remove weak cells efficiently.