Montana Rep. Denny Rehberg today responded to his opponent’s ad that rebuked his voting record on funding for cancer screenings with an ad of his own that features a cancer survivor very close to him — his mother.

The Republican is challenging Democratic Sen. Jon Tester in a race expected to be close until November. It’s also likely to get negative, highlighted most recently by the Tester ad. It featured a cancer survivor discussing how the cuts in an appropriations bill Rehberg supported could have affected her recovery.

The Rehberg ad is running statewide on broadcast and cable, and it cost the campaign close to $60,000.

“When Jon Tester says Denny Rehberg doesn’t care about cancer victims, he’s playing politics with a deadly disease,” Rehberg’s mother says in the new ad, though she doesn’t reveal their relationship until the end. “For 30 years, Denny has helped me battle cancer, from breast cancer, now to thyroid cancer, he’s been with me because Denny has a good heart and understands what cancer does to everyone it touches. I know, because Denny is my son.”