Two-pore channels (TPCs) are ancient ion channels present in the cells of both animals and plants. In animals, including humans, these ion channels play important roles in biological activities in various tissues, such as in the brain and nervous system. All land plant species contain TPC genes; in many higher vascular plants such as Arabidopsis thaliana (Arabidopsis) and Oryza sativa (rice), a single TPC gene is involved in the activity of slow vacuolar (SV) channels (voltage-dependent cation channels) along with long-distance signaling, defense, and responses to environmental stress. However, very little is known about the function of TPC proteins in non-flowering mosses and liverworts–some of the oldest organisms on Earth.