Life, a subtle balance

Life is a continuous balance between what needs to remain, and what must disappear. We are not aware of it but our bodies unceasingly shed cells that have received orders to die, which is a necessary process if tissues are to be renewed or to stay healthy. It does seem an odd paradox but this surprising phenomenon is an integral part of every living being and known as regulated cell death. There are different ways of dying, and cells are imaginative. One of the more select ways has been coined ferroptosis. Ferroptosis occurs when the level of iron-dependent lipid hydroperoxides has become toxic for a cell which is then left to perish. But before this occurs, cells have to be equipped with the necessary means to prevent precocious poisoning, or they will never be able to get on with what they are expected to. This regulation of the level of toxins is ensured by a special version of an enzyme known as glutathione peroxidase 4, or GPX4, that carries a very rare amino acid in its active site: selenocysteine. More