Biomarkers of Response to PI3K Inhibitors 37. Carracedo A, Ma L, Teruya-Feldstein J, Rojo F, Salmena L, et al. (2008) Inhibition of mTORC1 leads to MAPK pathway activation through a PI3K- dependent feedback loop in human cancer. J Clin Invest 118: 3065–3074. 38. Moores SL, Selfors LM, Fredericks J, Breit T, Fujikawa K, et al. (2000) Vav Family Proteins Couple to Diverse Cell Surface Receptors. Molecular and Cellular Biology 20: 6364–6373. 39. Zeng L, Sachdev P, Yan L, Chan JL, Trenkle T, et al. (2000) Vav3 Mediates Receptor Protein Tyrosine Kinase Signaling, Regulates GTPase Activity, Modulates Cell Morphology, and Induces Cell Transformation. Molecular and Cellular Biology 20: 9212–9224. 40. Barretina J, Caponigro G, Stransky N, Venkatesan K, Margolin AA, et al. (2012) The Cancer Cell Line Encyclopedia enables predictive modelling of anticancer drug sensitivity. Nature 483: 603–307. 41. Garnett MJ, Edelman EJ, Heidorn SJ, Greenman CD, Dastur A, et al. (2012) Systematic identification of genomic markers of drug sensitivity in cancer cells. Nature 483: 570–575. 42. Simon R (2005) Roadmap for Developing and Validating Therapeutically Relevant Genomic Classifiers. Journal of Clinical Oncology 23: 7332–7341. 43. Simon RM, Paik S, Hayes DF (2009) Use of Archived Specimens in Evaluation of Prognostic and Predictive Biomarkers. Journal of the National Cancer Institute 101: 1446–1452. PLOS ONE | www.plosone.org 13 September 2012 | Volume 7 | Issue 9 | e46518