Most of the therapeutic proteins (e.g. antibodies and hormones) are proteins that are secreted by human cells via the secretory pathway. Many of these therapeutic proteins are glycosylated during passage through this pathway and the glycans on the protein often play a crucial role in their pharmacological properties. At the moment, therapeutic proteins are produced in mammal cell lines. Construction of these lines is complex and culturing expensive. Mushroom forming basidiomycetes are interesting candidates for the efficient production of therapeutic glycoproteins. They have a glycosylation pattern which is more similar to that of humans than that of plants and other fungi. Within this project we will improve heterologous protein production in mushroom and will further humanize its glycosylation machinery.