About Lightner Lab

Dr. Mazer Ally is an adult Gastroenterologist and Clinical Assistant Professor of Medicine at Scripps Clinic, with a specialized focus on Inflammatory Bowel Disease. He completed both his undergraduate and medical education at The George Washington University. After commissioning into the U.S. Army, he completed his Internal Medicine Residency and Gastroenterology fellowship at the Walter Reed National Military Medical Center.

Before joining Scripps Clinic, Dr. Ally served as the Co-Director of the Inflammatory Bowel Disease Program at Walter Reed and as the Chief of Gastroenterology at Tripler Army Medical Center in Honolulu, HI. He also served in support of Operation Iraqi Freedom as a Squadron Surgeon for the 10th Mountain Division, earning the Meritorious Service Medal. Additionally, he served as a Battalion Surgeon for the 25th Infantry Division.

Dr. Ally has authored numerous publications and presented his research at national medical conferences, focusing on inflammatory bowel disease and eosinophilic esophagitis. He is an active member of national committees for the American College of Gastroenterology and the Crohn’s & Colitis Foundation. He is also a Fellow both of the American College of Gastroenterology and of the American Gastroenterology Association.

Outside of his professional life, Dr. Ally enjoys spending time with his family, as well as traveling, surfing, hiking, and running.

Zack holds Bachelor of Science degrees in chemistry and biochemistry/biophysics from Rensselaer Polytechnic Institute and a Ph.D. in Bio-Analytical Chemistry from the University of North Carolina at Chapel Hill. His doctoral research focused on advancing 3D cell culture techniques and integrating commercially available assays into complex 3D culture models. Prior to joining the Lightner group, Zack was a part of the Product Development team at Stemson Therapeutics, where he led the development of fit-for-purpose assays for the de novo hair follicle constructs being developed at Stemson. He is deeply passionate about 3D cell culture and committed to leveraging cutting-edge methods to create more physiologically relevant and accurate culture models.

Melissa Ferrari, PA, is a Physician Assistant within the gastroenterology department with a dedicated focus on Inflammatory Bowel Disease (IBD). She is experienced in the complicated nuances and medical management of Ulcerative Colitis and Crohn’s disease patients and has dedicated her career to their care. She works directly with IBD physician experts in order to provide a personalized approach for every patient.

Melissa believes positive outcomes are directly related to education and open communication. A patient that understands their condition, and the reason medications are being prescribed, is much more likely to be an active participant in their care. Melissa prides herself in providing excellent education and confirming management plans are mutually agreed upon and implemented.

Melissa is also very involved with the IBD community through the Crohn’s & Colitis Foundation and participates in many events for the Greater San Diego Area chapter.

Alexandra Silberstein is a Physician Assistant in the Division of General Surgery at Scripps Clinic in San Diego, primarily specializing in the surgical and medical management of inflammatory bowel disease (IBD). She earned her undergraduate degree in Human Development and Family Studies (HDFS) with a minor in Global Health from the University of Wisconsin–Madison. Later, she earned her Master’s degree from the Northwestern University Feinberg School of Medicine Physician Assistant Program, where she received the Clinical Excellence Award, served as vice president of her class, and was inducted into the Phi Alpha National Honor Society for academic achievement, leadership, and research.

During her time at Northwestern, she was first author on a paper published in the American Academy of Physician Assistants. She subsequently practiced emergency medicine for two years at Northwestern Lake Forest Hospital, serving as a clinical preceptor to PA students. She was also welcomed as guest instructional faculty at the Northwestern Feinberg School of Medicine PA program, she collaborated with faculty to design and implement point-of-care ultrasound (POCUS) curriculum and led simulation-based training in critical care and trauma management.

As a child of immigrants whose first language is Spanish, she brings cultural empathy and fluency to her clinical practice. Her academic interests include optimizing perioperative care and clinical research for IBD patients, advancing ultrasound-guided techniques, and developing innovative approaches to procedural education.

Grace is a second-year undergraduate student at UC Berkeley, majoring in Molecular and Cell Biology with an emphasis in Immunology and Molecular Medicine. Through her internships and undergraduate research, she has gained extensive hands-on experience in drug discovery, sparking a deep interest in immunology and translational research for incurable diseases. Grace is excited to further expand her research and clinical skills as a member of the Lightner Lab.