AC/DC have confirmed founder member Malcolm Young has left the band because of illness and is being replaced by his nephew.
A message on the heavy metal band's website said the y would go on without him and t heir new album, Rock Or Bust, will be released in December.
It said: " Unfortunately, due to the nature of Malcolm's condition, he will not be returning to the band. AC/DC will undertake a world tour in support of Rock Or Bust in 2015. Stevie Young, nephew of founding members Angus and Malcolm Young, plays rhythm guitar on Rock Or Bust and will accompany the band on tour."
Malcolm, who emigrated from Scotland to Australia at the age of 10 with his family, formed AC/DC in 1973 with his younger brother Angus, who has famously dressed as a schoolboy onstage for many years.
The band has previously survived the death of its singer when Bon Scott died in 1980 after a night of heavy drinking in London, to be replaced by Brian Johnson, who has remained as vocalist ever since.
They have been a huge draw on the rock circuit for decades, creating anthems such as Highway To Hell and Back In Black although they have tended to have album rather than single success. Their songs were used as the soundtrack for the movie Iron Man 2.
AC/DC's albums have been few and far between in recent years and their most recent release, 2008 chart-topper Black Ice, was only their third album since 1990.