News of Marvel creator Stan Lee's death has sent the pop-culture and geek worlds into a tailspin of grief and mourning today. Reactions from both fans and big names in both the Marvel Comics and the Marvel Cinematic Universe camps are still pouring in, and show no signs of slowing down anytime soon.

While we all try to cope with the loss of this iconic figure in the comic book medium, some fans are already beginning to wonder and/or worry about where Lee's presence in the Marvel Cinematic Universe will end - specifically the question of how many more MCU movie cameos from Lee fans will get to enjoy, before that longstanding tradition ends for good.

Right off the bat, let's establish one thing: before his passing, Stan Lee had already filmed his cameo for Avengers 4.

The first indication we got that Lee had turned in his Avengers 4 cameo scene came back in spring 2018, when Avengers: Infinity War directors The Russo Bros, revealed the following during a BBC Radio interview:

"He's the godfather of a lot of these stories, him and Jack Kirby," Joe Russo said "...So, Stan, typically we try to get him out — he doesn't love to fly — so we try to get him out for his cameos around the same time. So if we have other movies shooting on the same lot that we're on, for instance Ant-Man [and the Wasp] or Avengers 4, we group his cameos together and then move him from one set to the next and get him through his cameos in one day."

Lee appeared in Ant-Man and the Wasp this past summer (one of his best cameos), and as Joe Russo stated, that film Infinity War and Avengers 4 were all shooting around the same time, and a lot of the same studios. It was therefore easy to just shuffle Lee from one set to the other to film all the needed cameos, based on the way Joe Russo tells it.

The Russos also indicated that Stan Lee would be making cameos in Marvel movies 'well into 2019.' In addition to Avengers 4, Lee would likely have been able to film a cameo scene for the upcoming Captain Marvel - though that's not yet been concretely confirmed. The question gets a little bit trickier when trying to gauge if other studios also courted Lee for their 2019 Marvel movies. Sony's Spider-Man: Far From Home just wrapped principal photography, so it's a toss-up whether a Stan Lee cameo was added; even more vague is Fox's next X-Men movie release, Dark Phoenix.

At the very least, Marvel fans know that when Avengers 4 brings the first era of the Marvel Cinematic Universe to a close, it will get the extra poignant honor of having a milestone Stan Lee send-off to go with it.