MCU and neoplasm: In recent studies, altered MCU expression has been reported in cancer cells, and increased expression of MCU and alterations in proteins that regulate MCU channel activity have been associated with increased mtCa2+ and downstream effects that contribute to proliferation and tumor progression (Koval et al., 2019; Marchi et al., 2013; Ren et al., 2017; Tosatto et al., 2016; Vultur et al., 2018).