Stan Lee, whose contributions to the world of comic books turned the genre into what it is today, is the closest thing today's superhero blockbusters have to a father figure.

His presence as a cameo in every Marvel movie served as a repeated nod to his role in developing the many heroes that are beloved all over the world.

Following his death in 2018, however, many fans had a question on their minds: when will Lee's final cameo hit the big screen?

Though he filmed many of them ahead of time, fans were left uncertain as to how far his appearances would stretch.

Avengers: Endgame director Joe Russo, however, just cleared things up.

After previously being unsure of what Lee's final cameo would be, Russo spoke about Endgame to Mashable saying:

"It's his last one committed to film."

That makes it official—the rumored conclusion for many of Marvel's most well-known superheroes (like Iron Man, Thor, and Captain America) will also be the conclusion for their greatest champion, Stan Lee.

Though Lee's death remains a source of heartbreak for comic book and movie fans everywhere, Russo couldn't help but note how fitting Lee's final cameo is in the grand scheme of things.

"I have to say, I think it's astonishing that this would be his last cameo. It's just kind of mind-boggling that he made it to the end of this run. I can't believe it."

Joe's brother and co-director of Endgame, Anthony Russo, has spoken in the past about what a joy it was to work with Lee when he came on set for cameos.

"We have all these movie stars on that set, and when Stan came to set, everybody would be like kids again. It was always a lot of fun shooting these cameos because he was very charming, and he would maybe get the crew going, and everybody would be laughing and having a good time."

Twitter was understandably emotional about the news.

For Lee's final appearance to be in Avengers: Endgame seems only right.

Lee leaves behind tens of thousands of stories and an ever-growing army of fans.

He wrote about his life in the book he co-authored: Excelsior!: The Amazing Life of Stan Lee, available here.

Rest in peace, Stan Lee.

You will be forever missed.