They're remaining tight-lipped about who Ted's wife is, but the cast of How I Met Your Mother can't keep quiet about a cause close to their hearts.
The show's stars -- Jason Segel, Cobie Smulders, Neil Patrick Harris, Alyson Hannigan and Josh Radnor -- have partnered with the T.J. Martell Foundation in a newly-released public service announcement, urging viewers to send a $5 text message donation to help find a cure for cancer.
"We've all got friends and family who have been affected by cancer, and we've got to find a cure," says Smulders, who plays Robin, in the video.
The PSA hits home with many of the actors, including Harris, who told talk show host Ellen DeGeneres of his manager's struggle with cancer in 2008.
"We've been together 22 years," he says. "To watch someone go through that, it's so bizarre to see how many terrible steps there are in that process."
The T.J. Martell Foundation, founded in 1975, was named after a high school student who lost his battle with leukemia.
Carrie Underwood, Brad Paisley and Miranda Lambert have also volunteered for the group.
To donate $5 for the fight against cancer, text TJ to 90999. The one-time donation will be added to your monthly phone bill. For more information, visit the T.J. Martell Foundation's Web site.