Australian Olympic gold medalist Mack Horton had a suspicious mole removed recently thanks to an observant fan who urged him to get it checked out, according to CNN.
Friday, the 20-year-old swimmer posted on social media thanking the fan.
He wrote: "Shout out to the person that emailed the swim team doctor and told me to get my mole checked out. Good call. Very good call."
His Instagram post showed him with a bandage on his chest where the mole had been removed.
The swimmer didn't reveal any other details about what test results showed.
The Melanoma Institue Australia replied to his Facebook post saying: "We're glad to hear you had the mole checked out. Thanks for helping raise awareness about how important it is to get a skin check."
Another fan replied to his post saying, "So awesome for you to share this -- it's such a small thing to many people, but getting a check can save your life -- it saved mine!"
Horton won gold in the 400-meter freestyle at the Rio Olympics this year.
The Cancer Council Australia notes that about two in every three Australians will be diagnosed with skin cancer by the age of 70.