Aris Kaltsas, MD, PhD, is an Assistant Professor of Urology and Andrology at the School of Medicine, National and Kapodistrian University of Athens. He completed his medical degree, urology training, PhD, and postdoctoral research at the University of Ioannina. His clinical and research interests focus on reproductive urology and andrology, particularly male infertility, non-obstructive azoospermia, microsurgical sperm retrieval, varicocele, oxidative stress, sperm DNA fragmentation, the reproductive microbiome, and sexual medicine. He has authored more than 85 PubMed-indexed publications, serves as a Guest Editor and reviewer for international medical journals, and received the ISA Young Andrologist Award 2025.