My research line focuses on cellular differentiation programs that regulate the formation and homeostasis of the epidermis to get fundamental insights into the biology of skin barrier formation and cutaneous host defense mechanisms. This work is relevant for elucidation of monogenic diseases and the proposed role of compromised skin barrier function in development of inflammatory skin diseases like psoriasis and atopic dermatitis (AD). Furthermore, I pioneered microbiome research of human skin and I was the first from Europe to publish on this (Genome Biology 2012). I built a network for skin microbiome data analysis including a corporate partner (NIZO), sequencing provider (BaseClear) and bioinformaticians (CMBI). Using our skin microbiome analysis pipeline, we have recently smashed a major dogma in the most prevalent inflammatory skin disease, AD. We showed that the main genetic risk factor in AD affects the skin microbiota composition rather than causing a loss of skin barrier function (JACI 2017). Furthermore, we recently discovered that a psoriasis genetic risk factor acts via the skin microbiome (JID 2017). I initiated the development of human 3D in vitro skin microbiome models. These will be great assets for my two major ambitions: (1) to investigate how changes in microbiota composition affect the pathogenesis of AD and psoriasis, and (2) to develop new topical skin therapeutics, which will include microbiome-modifying agents such as pre- , pro- and anti-biotics.