Prof Peter Hordijk is working for Sanquin since 1997. He started as a staff member at the Department of Experimental Immunohematology. In 2005 he became head of the Molecular Cell Biology department. Hordijk is a specialist in the area of intracellular signaling in leukocyte transendothelial migration. The work of his group is focused on the role of small GTPases as well as specific cell adhesion molecules in the control of leukocyte and stem cell chemotaxis, leukocyte adhesion to endothelium and the modulation of endothelial integrity.