Enhancer Function of Integrated Alb Reporters 46. Nakabayashi H, Taketa K, Miyano K, Yamane T, Sato J (1982) Growth of human hepatoma cells lines with differentiated functions in chemically defined medium. Cancer Res 42: 3858–3863. 47. Fukushige S, Sauer B (1992) Genomic targeting with a positive-selection lox integration vector allows highly reproducible gene expression in mammalian cells. Proc Natl Acad Sci U S A 89: 7905–7909. 48. Locker J, Nalesnik M (1989) Molecular genetic analysis of lymphoid tumors arising after organ transplantation. Am J Pathol 135: 977–987. PLoS ONE | www.plosone.org 12 August 2011 | Volume 6 | Issue 8 | e23234