A team at UC San Diego says that protein kinase C (PKC) enzymes, long believed to spur tumor development, are in fact tumor suppressors. "For three decades, researchers have sought to find new cancer therapies based on the idea that inhibiting or blocking PKC signals would hinder or halt tumor development," said Alexandra Newton, a professor of pharmacology and the study's principal investigator, "but PKCs have remained an elusive chemotherapeutic target." The reason: The theory was just plain wrong. Release