HOUSTON -

The American Cancer Society is looking to unlock the mystery of cancer.

The Cancer Prevention Study-3 (CPS-3) will examine a diverse population of 300,000 people to better understand genetics.

"We just know it's aggressive and it's going to kill him," said Jennifer Walker.

Walker's 47-year-old father was normally a healthy man. She said he never had any medical problems.

"He had a grand maul seizure. Two weeks later, we found out he had terminal brain cancer," said Walker.

Fourteen months later, he was gone. In his honor, Walker is turning her pain into research.

"I'm enrolling in CPS-3 in his memory, a tribute to him. Hopefully, Hadley, my daughter doesn't grow up not knowing or losing people to cancer and not knowing what put them at risk," said Walker.

To qualify for the study, a person needs to be between the ages of 30 to 65 and have never been diagnosed with cancer. They must be willing to make a long-term commitment.

"This study will go on for the next 20, 30 years. You agree to participate you'll be contacted every two years," said Dr. Melissa Bondy, associate director for cancer prevention at Baylor College of Medicine.

It's a way for researchers to track a goal of 300,000 participants to better understand the causes of cancer.

"We might gain or lose weight, we might change physical activity, we might change other things. This study will gain information during the life course," said Bondy.

It's information that Walker is happy to share and track to try and understand how her father was diagnosed with cancer.

"You've put your DNA your unique asset into this study to find out what's causing or preventing cancer," said Walker.

In the Greater Houston Area, 19 community organizations partnered with the American Cancer Society to serve as host sites from May 11 to June 2. Call 888-604-5888 or visit www.cancerstudyGH.org to schedule an appointment.

The study has been going on since 2006 but it's closing in December.