Here's what we know: Jonah Hill has penned a cameo for Johnny Depp in the upcoming big-screen adaptation of "21 Jump Street." Depp, who starred as Officer Tom Hanson in the '80s TV series on which Hill's flick is based, is open to the idea of popping up in the movie, telling MTV News last year, "If we find the right thing to do, it could be very funny."

Here's what we don't know: Why haven't Hill and Depp been in contact about the possibility? Because as we learned while Depp was promoting "The Tourist" in Paris last week, he hasn't heard a peep about "21 Jump Street."

"I've said I'm into it, but no one's actually approached me," he told us.

As recently as last month, Hill said he's still hoping Depp will sign up for a part — "Just do it, dude. Don't be an a--hole," he joked — but as of now, Depp remains in the dark.

"Call him. I'm in. I'm in," Depp said. "I think it'd be pretty easy."

There's no word if Depp would reprise his role as Hanson or step into a new part, but Hill has told us in the past the film won't be a spoof of the original show but a "a hard-core, R-rated movie" that focuses on the fish-out-of-water scenario of cops returning to high school to pose as students in the name of undercover investigative work.

"What happens is, they get caught up in the high school-ness as opposed to the police work," he said last year. "And whenever they get too caught up in the high school drama, police work comes in. And whenever they get too caught up in the police work, high school drama comes in."

Check out everything we've got on "21 Jump Street."

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