Mitochondrial sodium/calcium antiporter that mediates sodium-dependent calcium efflux from mitochondrion, thereby acting as a key regulator of mitochondrion calcium homeostasis (Probable). Required for patterning of neural circuits: functions in the same pathway as RAC-dependent effectors of the unc-6/netrin signaling pathway to set left/ right patterning of the VD/DD GABAergic circuit (PubMed:28196860). Inhibited by the sodium/calcium exchanger inhibitor CGP-37157. Expressed in the seam cells of the organism. Expression is visible in the seam cells across all larval stages, and expression persists into the adult stage of the organism. Belongs to the Ca(2+):cation antiporter (CaCA) (TC 2.A.19) family. SLC24A subfamily.