Olly Alexander fought back tears after learning his new TV drama It's A Sin has led to an increase in HIV testing.
The Years and Years singer and the cast of his hit show reunited for a Zoom call on BBC Breakfast on Friday and discussed the impact the series has had on viewers.
"I've been blown away by how much it's touched people," he said. "But we were so touched when we read it! I'm still processing it.
"I've had really young gay people message me, saying they had no idea this happened and they can't believe it. This is a recognisable past, it's not that long ago. It's not hard for people to imagine what it was like - and they're seeing this treatment of gay people and they're just shocked. Of course you'd be shocked. How is this happening?"
Castmate Omari Douglas added, "Just seeing the viewing figures is absolutely insane," while co-star David Carlyle called the show's success "like a tidal wave!"
When the castmates were informed the popularity of It's A Sin has led to an increase in HIV testing across Britain, Olly teared up and said, "I'm trying not to cry! It's incredible to see a real time response to the show from the audience. I'm just really moved by it."
Omari added, "The fact that a piece of television has had such a cultural impact, but also the public heat impact is just crazy. It's so rare that telly has that effect."
Multi-BAFTA Award-winning writer Russell T. Davies' series follows a group of friends dealing with the outbreak of AIDS in the 1980s.
