Genetic susceptibility to lung tumorigenesis shows large variations among mouse strains. To test whether genetic predisposition to lung tumorigenesis is associated with a specific gene expression profile in normal lungs, we analyzed gene expression in 16 inbred strains of known susceptibility/resistance to lung tumorigenesis, using the RIKEN mouse full-length cDNA 19K microarray set. The strain-specific expression profile of 91 cDNA clones correlated with strain lung tumor susceptibility/resistance and predicted, by principal component analysis, the genetic predisposition to lung tumorigenesis in mice.