Marc Wilmore, a comedian, writer and younger brother of Larry Wilmore, has died at 57.

Marc Wilmore died from COVID-19, although his older brother said Marc had suffered from a variety of pre-existing health conditions ever since undergoing a kidney transplant in the 1990s.

Marc Edward Wilmore was born on May 4, 1963, in Fontana, Calif., and graduated from Cal State Polytechnic in nearby Pomona. His first big comedy break came in 1992 with a writing gig on In Living Color; he’d join the cast in the fifth and final season.

From there, he went on to write for Jay Leno’s Tonight Show, then to a writing gig on The PJ’s, followed by writing on The Simpsons, and finally F is For Family.

He famously pranked one of The Simpsons writers by showing up and pretending to be the outraged mayor of East St. Louis, Ill., then endearing himself so much he’d work on the long-running hit for some 15 years.