The prominent American transgender neuroscientist Ben Barres, known for his work with glial cells, the majority of brain cells that are not nerve cells, died Wednesday at the age of 63 years. He was diagnosed with pancreatic cancer two years ago, according to a press release from Stanford University, where he worked as a professor.

"Ben was a remarkable person. He will be remembered as a brilliant scientist who transformed our understanding of glial cells and as a tireless advocate who promoted equity and diversity at every turn,” Marc Tessier-Lavigne, PhD, president of Stanford University said in the press release. "He was also a beloved mentor to students and trainees, a dear friend to many in our community and a champion for the fundamental dignity of us all," he added.

Barres served as the chair of the neurobiology department at the Stanford University School of Medicine from 2008 to 2016. His research was mainly focused on the interaction between neurons and glial cells (collectively called glia); the latter form 90 percent of the human brain, which aren’t nerve cells but were once dismissed by scientists as being insignificant.

Through their work, Barres and his team made discoveries concerning the role of certain glial cells and also found out the molecular and cellular mechanisms underlying the kind of brain tissue degeneration seen in Alzheimer’s, Parkinson’s and Huntington’s diseases, and multiple sclerosis and glaucoma. He had once called this "the most important discovery my lab has ever made."

Thomas Clandinin, a professor of neurobiology, who would be Barres’ successor as chair of the department, said, "Ben pioneered the idea that glia play a central role in sculpting the wiring diagram of our brain and are integral for maintaining circuit function throughout our lives."

Barres joined as an assistant professor in Stanford University’s department of neurobiology in 1993. In total, Barres published 167 peer-reviewed papers during his career and was on the editorial boards of various journals, including Science, Neuron and Journal of Cell Biology.

Barres completed his graduation in neuroscience at Harvard Medical School in 1983 and in 1990, received his PhD in neurobiology. Following this, he continued his postdoctoral work under Martin Raff at University College London. Raff said, "If you took the Barres lab out of the field of glial studies, there would be no field," according to the Advocate.com.

Barres, a trans, had transitioned to male in 1997 and six years after that he became the first openly transgender scientist in the U.S. National Academy of Sciences.

Barres also bagged several awards for teaching and for his research work, including the Klingenstein Fellowship Award and a McKnight Investigator Award. In 2008, he also received the Mika Salpeter Lifetime Achievement Award, according to the Stanford University press release.

"Ben was a giant and will be dearly missed," Mary E. Hatten, Frederick P. Rose Professor of Neurosciences and Behavior at the Rockefeller University wrote after the news of his death.

The Alzheimer's Drug Discovery Foundation added: "The pipeline of drugs in development for #Alzheimers owes so much to Ben Barres. He was a visionary scientist and generous mentor."