Schwartz, R.E. et al. Proc. Natl. Acad. Sci. USA advance online publication (30 January 2012).

Induced pluripotent stem (iPS) cell lines generated from the somatic cells of individuals with disease offer the possibility to model both disease mechanism and the role of genomic variation in the disease process. Schwartz et al. now extend this notion to examine host-pathogen interactions, reporting an iPS model of hepatitis C virus infection. They demonstrate that hepatocyte-like cells derived from iPS cells, although of a fetal phenotype, express host factors needed for hepatitis C virus infection and support the entire viral life cycle for one viral genotype. The cells mount an anti-inflammatory response upon infection—including unpregulation of IL-28B, in which genetic variations are associated with varying response to hepatitis C treatment in humans.