Munc-18 (mammalian homologue of Unc-18) is a protein that is thought to be involved in regulating exocytosis due, at least in part, to it ability to bind syntaxin (Ciufo et al., 2005). Munc18-1 is a neuron-specific member of the Sec1/Munc18 protein family that binds to syntaxin1A and is thought to stabilize the complex (Liu et al., 2004). The function of Munc18-1 is thought to be regulated by phosphorylation.