Gene and Protein Expression Profiles After Treatment of Actinic Keratoses

Inclusion Criteria: * Participants should have a clinical diagnosis of actinic keratosis * Participants should be 18 years old or above * Participants must sign an informed consent Exclusion Criteria: * Known allergic reaction to either 5-fluorouracil , imiquimod, or melatonin * Immunomodulating treatment * Predictable poor compliance (due to i.e. dementia, substance abuse, psychiatric disease, life-threatening disease or language barriers) * Pregnant or breastfeeding * Females not in menopause (defined as no menstruation during the last 12 months) should use a secure birth control (intrauterine devices, hormonal contraceptives including - oral pills, patches, vaginal rings and injections) during the entire period of the trial