UNC13D and cancer: We propose that the increased expression of Munc13-4 in cancer cells after epithelial-to-mesenchymal transition combined with increased Ca2+ uptake (Yang et al., 2009; Feng et al., 2010; Prevarskaya et al., 2011; Sun et al., 2014; Didiasova et al., 2015) drives enhanced exosome release by highly aggressive cancer cells, and that Munc13-4 is a potential target for therapeutic intervention.