Frontline Cancer: Roughly 12 percent of all human cancers worldwide — more than 1 million cases per year — are caused by viral infections (called oncoviruses) and attributed to a relatively small number of pathogens: human papilloma virus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV) and Epstein-Barr virus (EBV). Given the emphasis upon other causal factors of cancer, such as genetic mutations or environmental sources, it’s a statistic that’s not well known nor, I would argue, fully appreciated. Human viral oncogenesis is complex, and only a small percentage of the infected individuals develop cancer, but that 12 percent translates into more than 500,000 lives lost each year to virus-caused malignancies. Many of those deaths are preventable because effective vaccines already exist for HPV and HBV. Right now. No future discoveries required.