John Mayer,Jimmy Kimmel and Jeff Ross took over hosting duties for their late friend Wednesday at an annual fundraiser for the Scleroderma Research Foundation, with the event raising $1.2 million for crucial research.
Bob hosted SRF's signature event, "Cool Comedy • Hot Cuisine," for 30 years before his death ... and this year's fundraiser featured a special video tribute to Bob, presented by John Stamos and Mike Binder.
Dave Chappelle showed up to the Beverly Wilshire for a surprise performance, even sharing a personal video message he got from Bob before he passed. Bill Burr joined Dave on stage for a couple jokes too.
Attendees plunked down $500 just to get inside the building ... and they chowed down on a sit-down dinner curated by celeb chef Susan Feniger.
Bob's sister, Gay, died from scleroderma -- a group of rare diseases that involve the hardening of the skin and connective tissue -- back in 1994 when she was only 47 ... and the SRF's annual fundraiser has now raised over $28 million for research to find a cure.