Runners from across the country are gearing up to participate in the largest marathon in the world this Sunday, many running on behalf of causes that are important to them.

Amy Cargain, of Mount Vernon, says she won’t let her battle with lupus stop her from completing the 26-mile run in the New York City Marathon.

Cargain tells News 12 Westchester that she was diagnosed with the auto-immune disease when she was 15 years old. She says that while it can prevent some from remaining active, she has pushed herself to run twice a day.

She says she has participated in countless local races since, running in honor of others fighting lupus and to show them they can do anything they set their minds to.

Cargain's boyfriend, Dino Fiorentino, says she has even pushed him to become healthier. Since they met, he has lost weight and stopped smoking. He says she has even inspired his kids to lace up their sneakers and run in a few events.

"Yes, there's times she doesn't feel good, but she's a fighter,” he says.

This year, Cargain is running on behalf of the Lupus Research Alliance with team Life without Lupus.