The fast-release sensors Syt1 and Syt2 are found in cortical and cerebellar PV+ neurons (as well as in a fraction of hippocampal BC) and ensure a fast and synchronous neurotransmitter release, contributing to the depressing profile of PV+ neurons’ synapses (Sommeijer and Levelt 2012; Bouhours et al. Here, SYT2 is linked to breast cancer.