- Kathy Hilton got upset in Aspen and Lisa Rinna shared all the off-camera details with the world.
- On the "RHOBH" finale, Rinna said she'd "get sick and die" if she didn't tell everyone about Hilton's actions.
The American Institute for Cancer Research denounced Lisa Rinna for saying she would "get cancer" if she did not call out Kathy Hilton in "The Real Housewives of Beverly Hills" season 12 finale.
Kyle Richards hosted a fundraiser for The Princess Grace Foundation at her home in the finale, which aired on October 5 . The ladies questioned why Rinna would share details about the off-camera drama that took place in Aspen at the event.
"I'm not going to take it to my grave 'cause I'd get sick and get cancer if I didn't express this. That's how bad it is to have these kinds of things go on and not express them," said Rinna.
"I'll get sick and die because it's that vile," she added.
A spokesperson from the American Institute for Cancer Research told TMZ that Rinna's comments were "certainly not based on reputable research."
They also accused Rinna of "using the specter of cancer as emotional blackmail to justify airing her grievance" and spreading "a popular (but likely false) concept" to the public.
Rinna's representative didn't immediately respond to Insider's request for comment.
Hilton, who is a friend of the show and not a Housewife, was frustrated by the core group's reluctance to help promote her tequila brand Casa Del Sol during the season's cast trip to Aspen.
Hilton reportedly had a huge meltdown at the Caribou club and then continued to behave erratically during the ride home. None of this was caught on camera, but Rinna chose to send texts to costar Erika Jayne throughout the evening that were shown on-screen during the season.
Rinna alleged that Hilton said, "I will take down this show single-handedly, I will fucking ruin you all," in reference to the cast of the show.
"The Real Housewives of Beverly Hills" airs Wednesdays on Bravo and on Hayu in the UK. Part two of the season 12 reunion airs October 19.