A novel regulator for membrane traffic in cells has been discovered by a team of scientists from the National Centre for Biological Sciences (NCBS), Tata Institute for Fundamental Research (TIFR) and the Babraham Institute. The molecule, Phosphatidylinositol 5-phosphate 4-kinase or PIP4K is a molecular overseer of membrane dynamics that functions as a negative regulator of endocytosis.