Piet van Erp is a Senior Scientist, Cell Biologist in the Dermatology Department of Radboud University Medical Center in Nijmegen, the Netherlands. He started as a lab technician, but obtained a Ph.D. in cytometry techniques for studying proliferation and differentiation of human keratinocytes in 1991. He is actively involved in skin research and has a long past-performance in the field of skin inflammation, epidermal growth and differentiation, and inflammatory skin diseases, especially psoriasis. His special interests are cytometry and cytomics, skin-material interactions, and product ergonomics in relation to skin. Current research areas are the pathogenesis of psoriasis, the mechanisms of action of existing and novel therapeutic interventions for psoriasis, and the application of in vivo reflectance confocal microscopy and other non-invasive tools for diagnosis and therapy monitoring of skin diseases.