Exact Sciences (NASDAQ: EXAS) now has a new celebrity endorsement. Actually, the company has two.On Monday, the molecular diagnostics company announced that musician, singer, and actor Harry Connick Jr. and his wife, former model Jill Connick, are supporting a campaign to raise public awareness about cancer screening. This campaign, dubbed "The New 50," seeks to encourage people ages 50 and older to talk with their healthcare providers about cancer screening alternatives, which include Exact Sciences' Cologuard DNA colon cancer test.But Exact Sciences stock dropped nearly 10% following the announcement of the company's new celebrity partnership before recovering to end the day down around 8%.