Aerosmith singer Steven Tyler has revealed he fought a secret battle with Hepatitis C three years ago.
Aerosmith have scored hits with Cryin' and Love In An Elevator
The star needed chemotherapy when he was diagnosed with the virus, which can cause fatal liver problems.
The treatment was successful, but it just "about killed me," he told US TV show Access Hollywood.
The World Health Organisation estimates that 170 million around the world people have the Hepatitis C virus, which is carried in the blood.
People with the infection can pass it on if their blood gets under the skin or into the bloodstream of another person - by blood transfusions, sharing needles, or by sexual contact, for example.
Tyler said he wants to raise awareness of the disease.
"Of all the people in this room, at least three have it and don't know it. It's the silent killer," he said.
"It's one of those things people don't speak about it, but it is treatable."
Aerosmith had their first US number one in September 1998 with ballad I Don't Want To Miss A Thing, from the soundtrack of the film Armageddon.
Their other hits include Cryin', Dude (Looks like a Lady) and Walk This Way.
Earlier this year, they were forced to cancel several US tour dates while Tyler had throat surgery.
The band are now back on the road with fellow metal band Motley Crue, and are due to release a greatest hits compilation, featuring two new songs, in October.