Gerrit is professor emeritus at the Faculty of Science. From 2011 until 2018 he was dean of the faculty. In 2018-2019, he was faculty professor.
By training he is a lipid biochemist/cell biologist, whose work originally focused on membrane viruses, epithelial lipid polarity and intracellular lipid traffic. With Kai Simons at EMBL, Heidelberg, he launched the idea of lipid sorting by means of lipid rafts. Subsequently he became interested in lipid translocation by lipid translocators (or "flippases"), like ABC transporters. His last experimental focus was on sphingolipid transport.
EMBO Member (2003), member of the Royal Netherlands Academy of Arts and Sciences (KNAW; 2008), member of the Academia Europaea (2017).