Dr. Gary R. Pasternack, former director of the Division of Molecular Pathology at the Johns Hopkins University School of Medicine and CEO of Asklepion Pharmaceuticals LLC, died Oct. 13 from heart failure at Levindale Hebrew Geriatric Center and Hospital. The longtime Roland Park resident was 74.

“Gary was known for his creative and detailed approach to science,” Dr. Ralph H. Hruban, professor of pathology and oncology at the Johns Hopkins University School of Medicine, wrote in an email to colleagues, who described Dr. Pasternack as a “modern Renaissance man.”

Dr. Jonathan R. Brody, who had been a student of Dr. Pasternack’s, is now vice chair of research and professor of surgery at Oregon Health and Science University.

“Gary was always an out-of-the-box thinker and pushed the envelope with his scientific studies that led to his entrepreneurial instincts,” Dr. Brody said.

Gary Roy Pasternack, the son of Louis P. Pasternack, a businessman, and Caroline Pasternack, a homemaker, was born in New York City and raised in Northbrook, Illinois, where he graduated from Northbrook High School.

In 1971, Dr. Pasternack earned a bachelor’s degree from Yale University and his Ph.D. in 1978 from Johns Hopkins University.

He returned to Yale, where he completed a fellowship and residency in pathology, and in 1984, joined the faculty of the Johns Hopkins University School of Medicine as an assistant professor.

In 1990, he rose to the rank of associate professor and went on to hold joint appointments in the departments of pathology, cell biology, anatomy, oncology and medicine.

From 1993 to 2005, he was director of Hopkins’ Division of Molecular Pathology and was the founder and first director of its Ph.D. Graduate Training Program in Pathobiology, which he headed from 1997 to 2005.

“It was Gary who got the program off the ground, which is very unique,” said Dr. Lee J. Martin, who succeeded Dr. Pasternack. “We train students that are global citizens who want to come and train at Hopkins and then go out all over the world. This is a major legacy of Gary’s.”

He described Dr. Pasternack as “outgoing, friendly, and unafraid to express his opinions,” but yet also a “down-to-earth individual.”

“He loved what he did and was so inspirational to me as a young person,” Dr. Martin said.

Dr. Pasternack, who favored bow ties, vests and tweeds, was, as one colleague described him, “quirky,” which led him to have students sometimes “answer questions in a haiku format and reference Kafka in his lectures,” Dr. Hruban wrote.

Dr. Pasternack’s work included advances in immunotherapy for cancer and the discovery of novel biomarkers for the detection and treatment of cancer. He held 29 patents and became an adjunct professor at Hopkins after leaving to join the biotech industry.

For the last 17 years, he had been CEO of Asklepion Pharmaceuticals LLC, a biopharmaceutical company based in Baltimore.

“At his death, he was seeking approval from the U.S. Food and Drug Administration for citrulline from ongoing studies at university and medical centers throughout the country, which would help alleviate the pain of those who suffer from sickle cell anemia and prevent hospitalization and illegal drug addiction,” said his wife of 44 years, Michelle Spicknall, a psychiatric social worker. “He was so passionate about that and worked very hard for the development of the drug.”

He was a former longtime board member and founder in 1992 of The Ingenuity Project, which assists city public school students in preparing for their future.

“He had no hobbies; his work and travel were intertwined,” Ms. Pasternack said.

He was a member of the Maryland Club, Green Spring Valley Hunt Club, Yale Club of New York City and the Naval and Military Club in London.

Plans for a memorial gathering are incomplete.

In addition to his wife, he is survived by a daughter, Sophie Pasternack, of Remington.