SYT12 is a member of the synaptotagmin gene family and encodes a protein similar to other family members that mediate calcium-dependent regulation of membrane trafficking in synaptic transmission. Studies of the orthologous gene in rat have shown that the encoded protein selectively modulates spontaneous synaptic-vesicle exocytosis and may also be involved in regulating calcium independent secretion in nonneuronal cells. Alternative splicing results in multiple transcript variants. SYT12 has previously been referred to as synaptotagmin XI but has been renamed synaptotagmin XII to be standard with mouse and rat official nomenclature.