I combine diagnostic and consultative activities in virology with research on transplantation-related infections. My focus is on persistent infections caused by DNA viruses, such as papillomaviruses (HPV), polyomaviruses (HPyV) and anelloviruses (TTV). I study their prevalence, diversity and pathogenicity, to understand why they create problems and identify strategies to prevent those. Moreover, I study if serological and molecular markers of these infections can be employed in the clinic, to prevent and overcome complications of (suboptimal) immunosuppression, such as transplant rejection and susceptibility for infection.