Solid organ transplant recipients (OTRs) receive lifelong immunosuppressive therapy, which puts them at increased risk of cutaneous and mucosal cancers. In particular, OTRs have increased risk of skin cancer and cancers caused by human papillomavirus (HPV), including cervical cancer and oropharyngeal cancer. There is currently limited knowledge on risk factors for HPV infection and skin cancer in OTRs, and limited knowledge on the natural history of HPV infection and cervical neoplasia in OTRs compared with immunocompetent controls. With a continuously increasing number of OTRs, there is a growing need to improve our understanding of the long-term reactions to immunosuppression. The overall aim of this study is to investigate long term effects of immunosuppression on cutaneous and mucosal epithelium in Danish OTRs, including the risk of skin dysplasia and skin cancer, cervical and oral HPV infection and HPV-related dysplasia and cancer in OTRs. This study will be designed as a prospective observational cohort study based on clinical data and data from nationwide Danish registries. A total of 600 female OTRs, 300 male OTRs and 600 female controls will be included from Danish dermatology departments. The study aims to provide knowledge relevant for improving prevention of skin- and HPV-related cancers in OTRs, including personalized screening recommendations according to individual patient risk.