09/28/2017 12:53 EDT | Updated 09/28/2017 12:54 EDT

Ryan Reynolds' SickKids Video Is A Powerful Reminder Kids Still Have Many Battles Ahead

The celeb stars in a new PSA for SickKids Hospital.

As a father to two young girls, Ryan Reynolds probably knows a thing or two about what it's like to see your child fall ill.

But it wasn't until he met a young cancer patient, Grace Bowen, who lost her life due to Osteosarcoma in 2015, that Reynolds decided he had to take action to help raise money and awareness for kids battling illness and disease.

Ryan Reynolds and Blake Lively with their, children attend the ceremony honoring actor Ryan Reynolds with a Star on The Hollywood Walk of Fame held on December 15, 2016 in Hollywood, California. (Photo by Michael Tran/FilmMagic)

Bowen was treated for the disease at Toronto's SickKids hospital, and although she passed away, she and the hospital left a mark on the Canadian actor.

"Like a lot of people who met Grace Bowen, I fell in love with [her]. I just saw how what she was going through affected everyone around her and how inspiring she was for everyone else," Reynolds told ET Canada last year.

So, at the end of 2016, the "Deadpool" star reached out to SickKids and asked how he could help. The 40-year-old ended up flying to the city to shoot a PSA.

Now, the Vancouver native is helping out the hospital again, this time with a new ad for the SickKids Foundation "VS" campaign.

According to a press release, Reynolds once again flew to Toronto on his own initiative (and cost) after expressing an interest in helping the hospital spread the word of the #SickKidsVS campaign and children's health.

300 @sickkidstoronto staff standing right behind me. Best superhero team-up movie ever.

A post shared by Ryan Reynolds (@vancityreynolds) on

In the video, the actor, who is joined by approximately 300 SickKids staff members, reminds viewers that although scientists, doctors, and researchers are making progress with diseases, "We aren't there yet, there are a lot of battles left to fight and we can't afford to lose a single one."

Ryan has also credited Edmonton's Connor McGrath, a 13-year-old who died from cancer last April, for helping him look for ways to help spread awareness about children's diseases.

In a tribute to his friend, Reynolds wrote on Facebook: "He went way too early and it's impossible to reconcile. Connor was a great friend, a great son, and a light to the people lucky enough to know him. While repeatedly punching cancer in the balls, he made everyone laugh. Including the entire staff who cared for him at Edmonton's Stollery Children's Hospital."

Connor was a great friend, a great son, and a light to the people lucky enough to know him.

He continued: "I'm grateful I got to orbit Connor's world for a brief time. Grateful for the pages and pages of hilarious texts between us. Grateful to his parents for allowing Connor to spend time with a foul-mouthed child in the body of a 39 year old."

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