Sam Polesie (S.P.) is a specialist physician working at the Department of Dermatology and Venereology at Sahlgrenska University Hospital. He defended his dissertation in 2019, and his PhD project was based on his own formulated question that appeared during an outpatient clinic. The question was whether methotrexate (MTX) increased the risk of melanoma. The first four parts of the dissertation consisted of epidemiological studies that used health care registries from the National Board of Health and Welfare and Statistics Sweden. Overall, MTX had only a minimal effect on the risk of developing melanoma. The studies have contributed to an increased understanding of the risk benefit assessment of MTX, especially for patients with a history of melanoma disease, where the results showed that the patients who had previously had a melanoma and then were exposed to MTX did not have a significantly increased risk of developing a new primary melanoma. The PhD-project has also led to a collaboration with the pharmacoepidemiological unit at the University of Southern Denmark in Odense and we are now compiling results from the Danish population to see if use of MTX is associated with the risk of skin cancer including melanoma. The interest in epidemiological studies is palpable and the most recently published study analyzed whether patients with psoriasis have an increased risk of developing melanoma. The study demonstrated a minimal increase in risk for melanoma compared to matched controls without psoriasis. The investigation contributes to an increased understanding of psoriasis and associated comorbidities. Since 2018, S.P. has conducted research in machine learning (ML). The work began with examining the attitudes towards artificial intelligence (AI) among dermatologists and dermatopathologists. These studies were initiated by S.P. and were conducted with international collaborators from the USA, Italy, Greece and Austria. Overall, attitudes towards AI were positive and both dermatologists and dermatopathologists saw great potential with an increased use of ML. The ML-related research has continued by developing applications in imaging that can prove valuable for healthcare. Although melanoma is usually easy to detect, it is often more difficult to discriminate in situ melanoma from invasive melanoma preoperatively. This classification problem is important since it may affect the selection of appropriate excision margin for the first operation. S.P. and co-workers have developed an algorithm that performs at the level of dermatologists. The work has received attention in press releases and media. The work of refining and developing the algorithm further is ongoing. The hope is to find applications that have practical importance for doctors in a real-life practice. S.P. conducts research on dermatoscopic findings that may distinguish between in situ and invasive melanomas. This research is carried out partly in collaboration with a research group in Austria. S.P. has experience in clinical studies and is a co-investigator in a prospective clinical trial that evaluates different treatment models for basal cell carcinoma. S.P. is involved as a co-author in several projects at the Department of Dermatology and Venereology and works closely with former co-supervisor Dr John Paoli (J.P.) and statistician Martin Gillstedt who is the statistician and data analyst employed at our department. During dermatology residency, S.P. worked a year at the departments of clinical genetics and clinical pathology. S.P. is interested in genetic diseases that affect the skin (genodermatoses) and has also co-authored a publication describing phenotypic traits in individuals with 12q12 duplications. Since 2021, S.P. also is engaged in the research group led by Dr Sirkku Peltonen, which will, among other things, investigate epidemiological aspects of genodermatosis in Sweden. Overall, S.P. has a profound interest in dermatology research and is an active supervisor. Since 2020, he has been the co-supervisor (main supervisor J.P.) for two doctoral students and has supervised four medical students in their degree project.