Non-selective channel that modulates the membrane potential under normal conditions and oxidative stress, and is involved in mitochondrial homeostasis (PubMed:25861990). Involved in mitochondrial deoxynucleoside triphosphates (dNTP) pool homeostasis and mitochondrial DNA (mtDNA) maintenance (PubMed:26760297). May be involved in the regulation of reactive oxygen species metabolism and the control of oxidative phosphorylation (By similarity). {ECO:0000250|UniProtKB:P19258, ECO:0000269|PubMed:25861990, ECO:0000269|PubMed:26760297}. This is the function of MPV17 (mitochondrial inner membrane protein MPV17, ENSG00000115204).