Dr. H.M. van Santen is a pediatric endocrinologist and clinical researcher dedicated to improving endocrine outcomes in children with oncologic and other diseases. Since 2013, she has led endocrine care for pediatric cancer patients at the Princess Máxima Center in Utrecht. An expert in hypothalamic dysfunction and pediatric thyroid cancer, she has co-authored over 150 papers and frequently delivers invited lectures worldwide. She is an associate professor at UMC Utrecht, coordinator of European Reference Centers for rare endocrine diseases, and chair of multiple national and international endocrine guideline groups, including the Dutch Pediatric Endocrinologists and the European Pediatric Thyroid Cancer Guideline. Her research focuses on hypothalamic dysfunction, craniopharyngioma, pediatric thyroid cancer, and endocrine effects of childhood cancer treatments.