MICU1 opens the gates to cold-induced death.

Nakamura et al. recently discovered that the mitochondrial calcium uniporter gatekeeper, MICU1, is required for cold-induced ferroptotic cell death by modulating mitochondrial membrane potential. This function appears to be independent of its Ca-sensing ability. Here, we discuss their findings and suggest next steps to define MICU1's role in ferroptotic cell death.