Chalid Assaf is Director of the Department of Dermatology and Venereology at HELIOS Klinikum Krefeld and the Health and Medical University (HMU) Düsseldorf–Krefeld, Germany (since 2009). He also serves as Head of the HELIOS Comprehensive Cancer Center Krefeld (since 2016) and, since 2025, as Dean of the HMU Medical School. He was appointed full Professor of Dermatology in 2019. Professor Assaf studied medicine at the Free University of Berlin and completed a fellowship at the John Radcliffe Hospital, University of Oxford, UK. He received his MD in 1997 and his PhD in 2001 for research on T-cell lymphoma diagnostics. He trained in pathology and dermatology in Berlin and later held positions at Charité – Universitätsmedizin Berlin, where he became Head of the Lymphoma Section of the Skin Cancer Center and Assistant Professor in 2008. He is board-certified in Dermatology and Venereology, with subspecialty certifications in Dermatopathology and Medical Tumor Therapy, and certification in Physician Quality Management. His clinical and research focus is on cutaneous lymphomas, including mycosis fungoides and Sézary syndrome, as well as melanoma and immunotherapy. He has received multiple awards, including the Berlin Foundation of Dermatology Research Prize (2013), and has authored over 200 peer-reviewed publications while contributing to international guidelines.