[1] He and Martin Rodbell shared the 1994 Nobel Prize in Physiology or Medicine "for their discovery of G-proteins and the role of these proteins in signal transduction in cells.

Immediately after graduation in 1962, he worked with Allan Conney at Burroughs Wellcome & Company, which resulted in the publication of his first two technical papers.

Persuaded by Earl Wilbur Sutherland, Jr., he joined Case Western Reserve University School of Medicine for an MD-PhD course.

His friend Michael Stuart Brown (who was also born in 1941, and later the 1985 Nobel Prize in Physiology or Medicine laureate) joked that Gilman was "probably the only person who was ever named after a textbook.

He grew up in White Plains, New York, while his father worked at Columbia University and Albert Einstein College of Medicine.

The school was known for its sports activity, and he described it as "a strict, monastic, and frankly unpleasant environment in the 1950s: academic boot camp.

[11][12] He then entered a combined MD-PhD program at Case Western Reserve University School of Medicine in Cleveland, Ohio where he wanted to study under Nobel laureate pharmacologist Earl Sutherland, who was a close friend of his father.

Gilman graduated from Case Western in 1969, then did his post-doctoral studies at the National Institutes of Health with Nobel laureate Marshall Nirenberg from 1969 to 1971.

[1] Nirenberg assigned him to work on the study of nerve endings (axons from cultured neuroblastoma cells), which he considered as "a truly boring project."

In 2005, he was appointed director of the drug company, Eli Lilly & Co.[15] Gilman died after a long battle with pancreatic cancer in Dallas, Texas, on December 23, 2015, at the age of 74.

He was survived by his wife and three children, Amy Ariagno and Anne Sincovec, both of Dallas, and Edward Gilman of Austin.

In 1970 Martin Rodbell found that hormones did not directly influence cyclic AMP, but there existed other molecules, the third messengers.

Rodbell discovered that cyclic AMP is activated when guanosine triphosphate (GTP) is released from the cell membrane.

This showed that the missing membrane protein was responsible for mediating hormonal signal to cyclic AMP by producing GTP.

He was the leader of scientists of the US National Academy of Sciences, including Nobel laureates, to publicly criticize the board in The Dallas Morning News.

He commented: "How can Texas simultaneously launch a war on cancer and approve educational platforms that submit that the universe is 10,000 years old?"

"[27] He received the Albert Lasker Award for Basic Medical Research as well as the Louisa Gross Horwitz Prize from Columbia University in 1989 together with Edwin Krebs.

He served on the board of advisors of Scientists and Engineers for America, an organization focused on promoting sound science in American government.