Bono is set to front Aslan at an upcoming charity concert for Christy Dignam.
They may come from opposite ends of Ballymun and be rock rivals, but at the same time they are the best of friends.
Now Bono has agreed to front Dignam's band at A Night For Christy in the Olympia Theatre next month.
The Herald has learned that the U2 singer has pledged his support to the night, which will see some of the biggest names in Irish pop and rock perform to help pay the medical expenses of the Aslan frontman, who is battling cancer.
"There are some people who are going to get up on the night, but we can't announce in advance because of the crowd-control situation. We're just not allowed to say who they are," guitarist Billy McGuinness said, announcing the concert on Tom Dunne's Newstalk programme.
Bono had been among the well-wishers to send Christy a personal message as he underwent chemotherapy during a 10-week stay in Beaumont Hospital being treated for two forms of blood cancer.
A handwritten card from Bono and his wife Ali was spotted by a visiting journalist.
Bono has vowed to support the benefit by turning up as one of the guest vocalists fronting Aslan on the night.
But he could have competition from Christy himself, who has vowed to take the stage himself if he's well enough.
"It really will be down to how Christy feels on the night. All we know is that we could fill the bill for this concert several times over such is the support we've had.
"It fact the line-up for A Night For Christy is better than most of the summer festivals this year and all as a result of goodwill for Christy," said Billy McGuinness.
Bono's pal Gavin Friday, Mark, Feehily of Westlife, Bressie, Danny O'Reilly (The Coronas), Horslips, Ryan Sheridan, Paul Brady, Shane MacGowan, Mary Black, Don Mescall, Tom Dunne (Something Happens), Jerry Fish, Steve Wall (The Stunning), Gavin Friday, Paul Walsh (Royseven) are among the artists performing.
Tickets from €30 including booking fee will go on sale from Ticketmaster outlets nationwide this Friday.