Lydia Gregg is a research associate and medical illustrator in the Division of Interventional Neuroradiology at The Johns Hopkins University School of Medicine and co-founder of ProAtlantal Studio with her husband and colleague, Fabian de Kok-Mercado.

Lydia received her Master of Arts in Medical and Biological Illustration from the Department of Art as Applied to Medicine at the Johns Hopkins University School of Medicine in 2007 after studying scientific illustration, figurative sculpture and biology at the University of Michigan. She has received honors including the Inez Demonet Scholarship, the Frank H. Netter MD Memorial Scholarship in Medical Art, and awards from the Illustrators Club, The National Arts Program and the Association of Medical Illustrators.