ST. CHARLES, MO (KTVI-FOX2now.com) - A St. Charles teen who won a battle with his insurance company is not winning the battle with cancer. But his will to help is just as strong as his will to live. "Happy birthday to you, happy birthday dear CJ," sings a small crowd to a frail CJ Aubuchon. He is turning 19 Sunday, and he's dying of cancer. He knows it. He says he is not afraid.

"I'm good. I'm doing the best I can," says CJ.

"It's not how we would've liked it to go," says his mother Jeanine, "but this is how it's going. So he's actually helping prepare his memorial service."

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The physical change in CJ in just one month is startling. In March, though he looked pale, he was walking and laughing and joking when he won a battle against the insurance company. After denying an experimental treatment three times, the company finally approved his family's fourth appeal. The treatment began within days, but then bad news came fast.

"It was just, the cancer was just moving too quickly," explains Jeanine.

CJ stopped the treatment, but he didn't stop living. His favorite charity had a fundraiser Saturday morning. CJ's team of nearly 100 people, raised a whopping $1,750. And it was the largest team Friends of Kids with Cancer had ever seen in nine years of walks.

"It's huge, it's huge," says Executive Director Judy Ciapciak. "Everybody just loves CJ."

Friends of Kids with Cancer supports young cancer patients and their families. Since CJ couldn't go to college, like most of his friends, he asked the charity to make his bedroom into a dorm. They gave him a big screen TV, a refrigerator, and a recliner. The money CJ helped raise will help kids just like him. Some who walked in his honor didn't even know him.

"Just bringing people together," says CJ. "It was awesome to see all my old friends. Wish I had more energy, but I'm extremely happy with everyone who showed up and helped out."

His body is failing, but his smile and spirit will never fade.

"CJ says I have to hang on," says Jeanine. "So I have to keep it together. Like CJ says, this is his journey. We're just going with him."

"We follow CJ," she says.

"Thank you to everyone who helped," says CJ.