BEGAIN and cancer: We found that NEDD4 binding protein 2-like 1 (<i>N4BP2L1</i>), pleckstrin homology domain-containing family A member 4 (<i>PLEKHA4</i>), and brain-enriched guanylate kinase-associated protein (<i>BEGAIN</i>) that are normally highly expressed in breast myoepithelial cells and smooth muscle cells were significantly downregulated in breast tumor tissues of a cohort of 50 patients with this cancer.