A toxin produced by mold on nuts and grains can cause liver cancer if consumed in large quantities. UC Irvine researchers have discovered what triggers the toxin to form, which could lead to methods of limiting its production. Because of lax or nonexistent regulation, 4.5 billion people in developing countries are chronically exposed to vast amounts of this toxin, called aflatoxin – often hundreds of times higher than safe levels. In places such as China, Vietnam and South Africa, the combination of aflatoxin and hepatitis B virus exposure increases the likelihood of liver cancer occurrence by 60 times, and toxin-related cancer causes up to 10 percent of all deaths in those nations. “It’s shocking how profoundly these molds can affect public health,” says Sheryl Tsai (pictured), UCI molecular biology & biochemistry, chemistry, and pharmaceutical sciences associate professor. Tsai is lead author of a study in the Oct. 22 issue of the journal Nature that reports the finding.