Ryan Reynolds is urging fans to join him in donating funds to a special cause.

Reynolds is friends with actor Rob Delaney, who just lost his two-year-old son Henry to brain cancer.

“Words fail in comparison to what my friend @robdelaney experienced,” tweeted Reynolds. “I‘m making a donation to http://rainbowtrust.org.uk  in Henry’s memory. If you’re inclined, you can too.”

Words fail in comparison to what my friend @robdelaney experienced. I‘m making a donation to https://t.co/bZoMqpHsQh in Henry’s memory. If you’re inclined, you can too. https://t.co/wezKBF1CYd

— Ryan Reynolds (@VancityReynolds) February 10, 2018

The tweet has been liked over 15,000 times and retweeted more than 1,500 times.

Reynolds’ chosen charity, Rainbow Trust Children’s Charity, describes itself as supporting “families who have a child aged 0-18 years with a life threatening or terminal illness”.

On February 9, Delaney announced that his son died in January after more than a year of battling brain cancer.

“I have very sad news,” he wrote on Facebook. “My two and a half year old son Henry has passed away. Henry had been diagnosed with a brain tumor in 2016, shortly after his first birthday, following persistent vomiting and weight loss. He had surgery to remove the tumor and further treatment through the early part of 2017. Then the cancer returned last autumn and he died in January.”

You can read Delaney’s full Facebook post below.