By Mark Strassman, CBS News

DALLAS (CBS News) – If you want to make it in the National Football League, you’ve got to be ready to make sacrifices. But for one player, it took a mother’s bravery to learn about real sacrifice.

For low-income women like Tammy Garrett,  the morning brings a ray of hope in the form of mobile mammograms.

Without the bus offering free screenings, Garrett said “I wouldn’t be able to get it at all.”

The program provided 4,500 women with mammograms last year. Twenty of them had breast cancer.

But there’s another story about how the bus and the mobile mammograms come into neighborhoods. It’s powered by a mother’s legacy, and a son’s commitment.

The son is Bradie James, a linebacker for the Dallas Cowboys. He started Foundation 56, a breast cancer outreach program. His mother, Etta James, died of the disease in 2001.

Click here to learn more about the Bradie James Cancer Resource Center

James said there was nothing like this for his mom. If there had been, he said, “She’d still be here.”

In 2000, Bradie James was a college standout at LSU. But at home, his father had kidney disease, while his mother fought breast cancer. They had little money.

Etta James Foundation 56 on Facebook

So Etta James passed up cancer treatment, to give her husband a chance at kidney treatment — and life.

“She chose to put herself on the back burner so everyone else could live,” James said. “I guess that’s the way she felt she could live – live vicariously through everyone else.”

Susan G. Komen Breast Cancer Foundation

His parents died within three months of each other.

James honors her memory through his motivational visits with support groups, like yoga and cooking classes.

National Cancer Institute: Breast Cancer

Cecelia Stephens said she’d be “dead” without Foundation 56. In 2008, Stephens walked onto a Foundation 56 bus – with Stage 3 breast cancer. After treatment, now she’s cancer-free. Stephens always wanted to meet James to thank him. When she finally got the opportunity, she gave him a big hug.

In every woman James helps, one in particular comes to mind. “It’s all about her legacy and a son’s love for his mom.”