A well-known potassium channel plays a critical role in lysosomes.

Whole-endolysosome patch clamping presents new opportunities to identify and characterize channels pivotal for these acidic organelles. In this issue (Wang et al., 2017. J. Cell Biol. https://doi.org/10.1083/jcb.201612123), the identification of a role for the large conductance calcium-activated potassium channel brings new thinking about regulation of lysosome membrane potential and function.