Boceprevir and Telaprevir, first generation NS3 PIs, were approved in the 2011 in United States by Food and Drug Administration and Europe (FDA) by European Medicines Agency (EMA) for therapy of chronic hepatitis C. These drugs, however, administered in combination with peg-IFN and ribavirin were hampered by a low efficacy against non-1 genotypes, serious adverse reactions and low genetic barrier to resistance. The gene discussed is KRAS; the disease is chronic hepatitis C virus infection.