Meet the Team

Makoto Ishii, M.D., Ph.D.

Makoto Ishii, M.D., Ph.D.

Principal Investigator & Assistant Professor

Dr. Makoto Ishii is a board-certified neurologist and a physician-scientist dedicated to both patient care and biomedical research focusing primarily on Alzheimer’s disease and related neurodegenerative disorders. He received his BSE from Princeton University and then enrolled in the Tri-Institutional M.D./Ph.D. Program in New York. Dr. Ishii completed his graduate studies with Dr. Jeffrey Friedman at The Rockefeller University where he examined the role of hypothalamic genes in the regulation of body weight and metabolism. After completing his clinical training in neurology at Weill Cornell Medical College, he joined the faculty at Weill Cornell Medicine to start his research program. His laboratory was the first to identify that amyloid-beta, a pathological driver of Alzheimer’s disease, can disrupt select hypothalamic neurons and leptin-signaling pathways leading to body weight and systemic metabolic deficits prior to significant memory impairment. Dr. Ishii joined the faculty at UT Southwestern in 2023, where he continues to provide clinical care at the Memory Clinic and lead a research laboratory with ongoing studies seeking to elucidate the molecular mechanisms underlying the body weight, neuroendocrine, and behavioral deficits in Alzheimer’s disease and related dementias. 

Nil Saez Calveras, M.D.

Nil Saez Calveras, M.D.

Neurology Resident  

Dr. Saez Calveras was born and raised in Spain and received his medical degree from the University of Barcelona. During medical school, Dr. Saez Calveras also worked as a research intern at the Massachusetts General Institute for Neurodegenerative Disease in Boston under the mentorship of Dr. Teresa Gomez-Isla. There, he focused on validating new Tau PET radiotracers for Alzheimer's disease and Chronic Traumatic Encephalopathy. Dr. Saez Calveras moved to Dallas to start his residency as a research track resident in the Department of Neurology at the University of Texas Southwestern Medical Center. Currently, Dr. Saez Calveras is working with Dr. Ishii on evaluating the structural changes in the hypothalamus and other key brain regions in Alzheimer’s disease and aging and examining their relation to systemic metabolic, cognitive, and behavioral measures. 

Cali Warren, M.S.

Cali Warren, M.S.

Research Assistant  

Cali Warren grew up in Frisco, Texas. She attended Brigham Young University in Utah, earning both her undergraduate degree in microbiology and her master’s degree in cell biology and physiology. She previously worked on research projects focused on mitochondrial function, ketones, and insulin resistance in a metabolism lab for five years under the mentorship of Dr. Benjamin Bikman. Currently, Cali is working in the Ishii Lab studying how body weight, systemic metabolism and hypothalamic function are altered in Alzheimer’s disease. In her free time, Cali enjoys going to concerts, working out at Hotworx, trying new food and coffee shops, watching baseball, and spending time with her cat, Mazie.

Ian Chen, B.A.

Ian Chen, B.A.

Research Technician   

Ian Chen was raised in Kaohsiung, Taiwan before moving to California in the sophomore year of high school. He earned his undergraduate degree from Swarthmore College in 2024, graduating with a major in neuroscience and a minor in chemistry. Currently, Ian is working in the Ishii Lab studying the role of the hypothalamus in Alzheimer’s disease. Outside of the lab, Ian enjoys playing sports such as tennis or volleyball, immersing himself in fantasy novels or shows, and pursuing self-improvement projects like playing the guitar and learning a new language.

Hannah Hittson, B.S.

Hannah Hittson, B.S.

UTSW Medical Student, Class of 2027    

Hannah Hittson grew up in Dension, TX (where Dwight D. Eisenhower is from!) and received her bachelor’s degree in biochemistry from Baylor University. Hannah then attended Duke University for graduate school, where she studied the intersection of religion and medical ethics. In her free time, she loves to walk her dog Koda, go camping, and climb! Currently, Hannah is working with Dr. Ishii on studying the role of the hypothalamus in Alzheimer’s disease.