Hepatitis C virus (HCV) and HIV infections are of high economical importance as they have a global impact, high mortality rates and, consequently novel treatments are urgently needed. Worldwide, 170 and 34 - 46 million people are infected with HCV and HIV, respectively. HCV and HIV medications constitute the largest antiviral markets today. The efforts in fighting HCV infections are still limited to early clinical development, trying to establish proof-of-concept in man. However, in HIV, there is a better chance that some of the new drugs on new and old targets (indirect and direct antiviral targets, like CCR5 and HIV protease, respectively) will finally reach the market.