Both spontaneous, and evoked neurotransmitter release is affected by lowering the levels of STXBP1 in many animal models.17–20 These results are consistent with the observation that at functioning synapses STXBP1 is crucial for the assembly of the SNARE complex, a collection of proteins involved in the fusion of vesicles with the plasma membrane,21–23 variants in several of which are implicated in neurodevelopmental disorders and epilepsy (collectively, termed SNAREopathies9). Here, STXBP1 is linked to neurodevelopmental disorder.