If you follow Mitch Marner on Twitter, you may have noticed he wished a special friend of his a Happy Birthday recently.

Hayden Foulon is the friend Marner wished a Happy 6th Birthday.  She's been friends with Mitch since 2015 when he was with the London Knights and met her for the first time at the hospital.

Hayden has battled acute-lymphoblastic leukemia for more than four years and the London native has had cancer since she was 22 months old.

Her spirits are high, though, and she's got a wonderful friend in Marner, who sent her this incredible gift for her birthday.

Hayden's mom detailed to NHL.com her daughter's reaction to receiving the gift and seeing the tweet.

"When we saw that [Marner] had posted a message on Twitter, along with the picture, it made her feel so special," Hayden's mom, Lindsay Foulon, told NHL.com. "When the signed canvas arrived, calling her his friend, she grinned from ear to ear, and her smile melted my heart."

Marner has been supporting Hayden and putting a smile on her face ever since they met, and their friendship is a wonderful reminder of the incredible impact athletes can have outside of their sport:

"He has been an important part of Hayden's cancer journey, and their friendship has been something to make her smile on days when she felt like doing anything but [smiling]," Foulon said. "So many kids look up to professional athletes as role models, and based on our experience with Mitch, Hayden couldn't have picked a better, more stand-up guy. He's got fans for life in our family."

(H/T: NHL.com)