Dikembe Mutombo, a Basketball Hall of Famer who was one of the best defensive players in NBA history and a longtime global ambassador for the game, died Monday from brain cancer, the league announced. He was 58.

His family revealed two years ago that he was undergoing treatment in Atlanta for a brain tumor. The NBA said he died surrounded by his family.

“Dikembe Mutombo was simply larger than life,” NBA Commissioner Adam Silver said. “On the court, he was one of the greatest shot blockers and defensive players in the history of the NBA. Off the floor, he poured his heart and soul into helping others.”

Mutombo was distinctive in so many ways — the playful finger wag at opponents after blocking their shots, his height, his deep and gravelly voice, his massive smile. Players of this generation were always drawn to him and Philadelphia 76ers star Joel Embiid, who was born in Cameroon, looked to Mutombo as an inspiration.

“It’s a sad day, especially for us Africans, and really the whole world,” Embiid said Monday. “Other than what he’s accomplished on the basketball court, I think he was even better off the court. He’s one of the guys that I look up to, as far as having an impact, not just on the court, but off the court. He’s done a lot of great things. He did a lot of great things for a lot of people. He was a role model of mine. It is a sad day.”

Mutombo spent 18 seasons in the NBA, playing for Denver, Atlanta, Houston, Philadelphia, New York and the then-New Jersey Nets. The 7-foot-2 center out of Georgetown was an eight-time All-Star, three-time All-NBA selection and went into the Hall of Fame in 2015 after averaging 9.8 points and 10.3 rebounds per game for his career.

He also was part of one of the league’s most iconic playoff moments, helping eighth-seeded Denver oust top-seeded Seattle in the first round of the 1994 Western Conference playoffs. That best-of-five series marked the first time a No. 8 beat a No. 1 in NBA history.

“It’s really hard to believe,” Toronto President Masai Ujiri said Monday, pausing several times because he was overcome with emotion shortly after hearing the news of Mutombo’s death. “It’s hard for us to be without that guy. You have no idea what Dikembe Mutombo meant to me. … That guy, he made us who we are. That guy is a giant, an incredible person.”

Mutombo last played during the 2008-09 season, devoting his time after retirement to charitable and humanitarian causes. He spoke nine languages and founded the Dikembe Mutombo Foundation in 1997, concentrating on improving health, education and quality of life for the people in the Congo.

And on occasion, LeBron James pointed out with a laugh on Monday, Mutombo didn’t necessarily improve the health of others.

“My fondest memory of Dikembe Mutombo? He fractured my face on my birthday in Cleveland with an elbow,” James, the Los Angeles Lakers’ star, said while taking several minutes Monday to pay tribute to Mutombo’s life. “I never even got an opportunity to tell him about that. “