Gareth Bale, the world's most expensive footballer, has pulled a pair of pants over his £85 million head, in support of a campaign to find a bone marrow donor for an eight-year-old-girl.
Hollie Clark was diagnosed with the rare condition, myelodysplastic syndrome (MDS) two months ago, leaving her reliant on regular blood transfusions.
To help find a suitable donor her family, who live in Cardiff, launched a social media campaign calling on people to take a picture with their pants on their head, posting the photo alongside the hashtag #pantsonyourhead.
Welsh striker Gareth, 24, is the most famous face to join the search for a donor. A host of stars, including Russell Howard, Welsh rugby player Sam Warburton and rugby commentator Jonathan Davies have all posted selfies to ask people to sign up to become bone marrow donors.
Gareth posted a picture of himself on Twitter sporting a pair of white boxers on his head with the 'firstname.lastname@example.org' message stitched into the elasticated waist.
The footballer tweeted: "Hollie is in need of a bone marrow transplant, please RT! #pantsonyourhead @HelpHollie @HolliesParents."
- Gareth Bale (@GarethBale11) June 30, 2014
The campaign was launched earlier this month by Hollie's family and her mother, Laura, said there has been a huge increase in the number of donors signing up in the weeks since the appeal began.
Hollie was diagnosed with MDS – a blood disorder which causes a drop in the number of healthy blood cells in the body - in April this year after developing unusual bruising.
The family came up with the idea for the #pantsonyourhead campaign while Hollie was in a hospital bed following her first treatment.
Laura said: "At the time the only way some of our family could communicate with her was by using FaceTime videos on their phones.
"Her uncle, Matthew put his underwear on his head to make her laugh while he was talking to her on FaceTime and it sparked an idea for a way we could raise awareness about Anthony Nolan in a way that's fun and personal to Hollie.
Hollie and her family. Pic from HelpHollie.com
"We are reaching out, and every single person in the public can help. If they are too old to donate bone marrow they can still donate blood.
"It has been absolutely amazing. We have not got a match yet, but right from the start we said it was about finding a match and about raising awareness and we have definitely done that.
"We would love to personally thank everyone."
Hollie's family has asked people aged from 16 to and 30 to register with Anthony Nolan.
Karen Archer, Regional Register Development Manager at Anthony Nolan said: "The 'pants on your head selfie' idea has really taken off and is making a big difference in terms of the numbers joining the register."