Collaboration albums in hip-hop are nothing new. Jay Z has teamed up with R. Kelly and Kanye West  for albums, and most recently, Drake and Future released “What a Time To Be Alive.” But the latest rumored joint album involves two of hip-hop’s best rappers.

Since 2011, rumors about a joint album between J. Cole and Kendrick Lamar have swirled. Although we don’t know much about the album, a rapper close to Kendrick has confirmed the album does exist. Whether the album turns out to be an EP or a full-blown album, here’s everything we know about the rumored project.

Ab-Soul Says It’s Real

On Dec. 9, during an interview with Power 105’s “The Breakfast Club,” rapper Ab-Soul — a member of Kendrick Lamar’s group, Black Hippy — said the album does exist. “There is a Kendrick-Cole album. They got it. They got something in the works.” The rapper went on to say Kendrick and Cole have been working on the album for awhile. 

He Said He Recorded For The Album

While Ab-Soul wasn’t able to reveal if he has a feature on the album or how many songs are on it, he did say he hopes his verse gets used. “I don’t really know too much about it. I just hope they use my verse.”

J. Cole Mentioned The Album On A Song

In 2015, Kendrick and Cole both released songs called “Black Friday.” On Kendrick’s song, he rapped over the beat of J. Cole’s “A Tale of Two Citiez,” while J. Cole rapped over Kendrick’s “Alright.” But it was Cole’s version of the song that featured him saying the album would never release because the world couldn’t handle him and Kendrick together. It’s uncertain if Cole’s lyric was tongue-in-cheek or if it was true.

Kendrick Lamar’s Sister Once Revealed A Release Date

Although the album has never been confirmed, Kendrick’s sister, Kayla Duckworth, once said the project would release on Feb. 16, 2016. Obviously the album never came, but it seems like Duckworth had reason to believe the collaboration was nearly complete. 

Producer Oddisee Says The Album Exists

During an interview with Tim Westwood, producer Oddisee said he recorded a song with the two in 2012, but it never saw the light of day. “Everybody keeps talking about that record. They’re doing fine without that record. I’m doing fine. It does exist.”

They’ve Been Talking About It Since 2011

Rumors about the album are nothing new and have been around since 2011 when J. Cole told MTV, “Me and Kendrick doing a whole ridiculous thing together that’s gonna tear up the world.” That same year, Kendrick said, “Everything's going to be 90 percent produced by him, me busting over them… We got some records man.”

In 2013, Cole then said, “We already got too many songs. Even if you just get an EP, you gonna get something… We holding in the stash.” Two years later, Kendrick eventually said, “Yeah, definitely. I still would love to do it… We’re gonna try and make something happen.”