Actor David Lander, best known as Squiggy on the ABC sitcom “Laverne & Shirley,” died Friday evening at Cedars-Sinai Medical Center in Los Angeles, his family confirmed to Variety. He was 73.

Lander died of complications related to multiple sclerosis, which he battled for 37 years. Since he went public with his diagnosis in 1999, Lander has worked closely with the National Multiple Sclerosis Society, speaking out about his experience at related conferences.

The actor played the role of Andrew “Squiggy” Squiggman on “Laverne & Shirley,” opposite actor Michael McKean’s Lenny Kosnowski. The characters were developed by the longtime friends and collaborators while they were students at Carnegie Mellon University.

On Saturday morning, McKean remembered the late actor by tweeting an old photo of him and Lander.

Born on June 22, 1947 in Brooklyn, N.Y., Lander had his eyes on acting from a young age, and attended the High School for the Performing Arts in New York City. After teaming up with McKean in college, Lander moved with him to Los Angeles, where the duo joined the comedy ensemble. The Credibility Gap.

The actors continued building their early career together, co-starring in Steven Spielberg’s comedy film “1941” and Kurt Russell’s “Used Cars.” Lander and McKean also voiced an animated TV series, “Oswald,” in which they played the animated penguins Henry and Louie, respectively. In 1979, they released an album together as Lenny and the Squigtones featuring Christopher Guest in guitar, who was credited as Nigel Tufnel – an alias that Guest later reused in the fictional band Spinal Tap.

Lander also made appearances in several TV shows, including “The Bob Newhart Show,” “Barney Miller,” “Happy Days,” “Viva Valdez,” “Twin Peaks” and “The Drew Carey Show,” and played smaller yet memorable parts in movies like “A League of Their Own” and “Say It Isn’t So.”

As a voice actor, Lander was the voice behind Smart Ass in the 1988 Disney movie “Who Framed Roger Rabbit,” and was credited as Stephen Lander in “Boo” and “Zino and the Snurks.” He also voiced Ch’p in the DC Comics animated movie, “Green Lantern: First Flight” in 2009.

Lander most recently voiced Rumpelstiltskin in Disney’s children’s show, “Goldie & Bear,” and Donnie the Shark in an episode of “SpongeBob Squarepants” in 2016.

Lander is survived by his wife, Kathy Fields Lander, and daughter, Natalie Lander.