Hot 97, the station where Mister Cee built his foundation, sent out a heartfelt statement to signify his life and career ... "As a family at HOT 97 and WBLS, we’re deeply saddened by the passing of our beloved Mister Cee. He wasn’t just a DJ; he was a pillar of our stations, bringing joy to countless listeners with his legendary 'Throwback at Noon and Friday Night Live' sets."

The station adds ... "Mr. Cee’s influence stretched far beyond the airwaves, shaping the very fabric of NYC’s DJ culture. Our hearts are heavy as we send our love and condolences to his family and the fans whose lives he touched through his music. Rest easy, Mr. Cee. Your legacy will live forever."

50 Cent -- who defended Cee in 2011 amid his string of legal troubles -- was among the notable hip hop mourners paying respect to Cee's contributions to the culture.

Born Calvin LeBrun in Brooklyn, Cee got his start deejaying for Big Daddy Kane but is largely credited for discovering Notorious B.I.G. in the early '90s ahead of his signing with Diddy's Bad Boy Records -- his 'Best of Biggie' mixtape is hailed as one of the greatest street projects to be released.

At the time of his death, Cee was still actively working at the radio station and uploading his radio mixes to his Soundcloud account. He was known as "The Finisher" ... but his legacy is undoubtedly everlasting.

Cee was 57.