During the academic year 2010–11 he was on leave of absence from the University of Münster in order to serve as the first full-time professor of Coptology at the American University in Cairo.
Während des akademischen Jahres 2010–11 war er von der Universität Münster freigestellt, um als erster hauptberuflicher Professor für Koptologie an der American University in Cairo zu arbeiten.