The chloride ion channel ASOR is found in almost all our cells. But apart from its involvement in cell death, not much is known about its physiological role. Two years ago, researchers of the FMP and MDC led by Prof. Thomas Jentsch were able to identify the gene encoding this acid-sensitive ion channel. Now, in collaboration with Prof. Long (New York), they have gained astonishing insight about its structure and activation mechanisms. The findings, now published in Science Advances, are another step on the way to solving the puzzle of ASOR.