Keanu Reeves has donated 70% of his salary from the first The Matrix film to fund leukemia research - after his younger sister battled the disease for 10 years.
The actor, 57, who was reportedly paid $10 million upfront and earned $35million total for the first film in the franchise in 1999, was inspired to fund research into the type of cancer after his sister Kim, now 55, was diagnosed in 1991.
Keanu became Kim's primary carer during this time and helped with her recovery after she spent a decade fighting cancer, before going into remission, per Daily Mail.
The Speed star's devotion to his sister saw him sell his home to be closer to her and the Matrix sequels delayed - he also reportedly spent $5 million on therapies to help Kim recover.
He has previously said of his sister: "She was always there for me, you know. I will always be here for her."
The acclaimed actor has since launched a charity foundation to help those battling cancer.
In 2009 he told Ladies Home Journal: "I have a private foundation that's been running for five or six years, and it helps aid a couple of children's hospitals and cancer research. I don't like to attach my name to it, I just let the foundation do what it does."
Reeves has always been upfront about his relationship with money, highlighting that it "doesn't mean anything" to him.
He famously once said: "I've made a lot of money but I want to enjoy life and not stress myself building my bank account. I give lots away and live simply. We all know that good health is much more important."
The Matrix Resurrection is the long-awaited fourth installment in the Matrix franchise. Reeves is stepping back into his iconic role Neo after almost two decades since the third film was released.
The actor recently spoke about how his body handled the physical strain of stunts and fights now that he isn't as young as he used to be.
"You have to recover differently," said the star. "You have to pay a little more attention to that. Okay - a lot of attention to that. And I can't do what I used to but I can still do what I do."
Alongside Reeves, the fourth Matrix movie will also see the return of original cast members Carrie-Anne Moss and Jada Pinkett-Smith.