Nick Cannon is opening up about his new pediatric cancer foundation created in honor of his son, Zen, who died of brain cancer in December. «I'm a true believer in turning your pain into purpose,» Cannon told ET exclusively while at the Los Angeles stop of his Wild n Out rap battle tour. «To know how much joy that he brought our family, I just wanted to spread that light.»Cannon announced the Zen's Light Foundation alongside his son's mother, Alyssa Scott, on Friday, one day after what would have been Zen's first birthday.