Marvel superheroes join forces to make a sick fan smile

The Australian native, 17, battled leukemia since he was 5 and was diagnosed at age 15 with glioblastoma, the same form of brain cancer that Senator John McCain died from Saturday, according to the family's GoFundMe page. 

Over the past weeks, celebrities flipped the script on Josh, calling him their hero. Reynolds, who dubbed himself " Uncle Deadpool," told the teen he is thinking of him (Deadpool is Josh's favorite superhero).

"It's pretty much a fact that you have more courage and more strength in your pinky finger than any superhero does in their entire body," Reynolds said in a video message.

Evans jokingly gave Josh a hard time for being a bigger Deadpool fan than Captain America, the superhero he portrays in the Marvel Universe. Evans also sent his get-well wishes: "Hope you're doing good today and take care."

Pratt also joined in and sent a video message to Josh that is out of this world.

The "Guardians of The Galaxy" actor, who portrays Star-Lord, said: "I think real heroes are young people like you have to face challenges and do so with the bravery... that you do."

Pratt added that he hopes his heartfelt words will "help put a smile on your face."

Tom Holland's spidey senses must be tingling because the "Spider-Man: Homecoming" star hopped in on the action. He said, "I am thinking about you and everyone at Marvel is thinking about you."

The actor added that he is "filming Spider-Man, far from home."

Hugh Jackman, aka Wolverine, encouraged Josh to stay strong like the mutant he plays in the "X-Men" film series, adding: "I am sending you lots of positive thoughts, keep fighting."