Botulinum toxin type C (botC, also known as BoNT/C) is only very rarely associated with human disease (Hatheway 1995) and a pathway by which it might enter the circulation from the human gut has not been described. Nevertheless, the toxin itself, a disulfide-bonded heavy chain (HC) - light chain (LC) heterodimer (“dichain”), is capable of binding to neurons by interactions with cell surface gangliosides (Karalewitz et al. 2012), the bound toxin can enter synaptic vesicles and release its LC moiety into the cytosol of targeted cells (Montal 2010), and the botC LC can cleave synaptosomal associated protein 25 (SNAP25) and syntaxin 1 (STX1) on the cytosolic face of the neuronal plasma membrane (Foran et al. 1996). These four events are annotated here.