MAP2K1 and breast cancer: To further benchmark the predictive accuracy of MPAS against other gene expression-based predictors of drug sensitivity, we used data generated in the DREAM Drug Sensitivity Prediction Challenge, which engaged 45 bioinformatics teams using gene expression data from 32 breast cancer cell lines to predict sensitivity of 18 blinded cell lines to drugs (including the MEK1/2 inhibitor PD184352).28 While the set of cell lines and MEK1/2 inhibitor used were different, the results from DREAM still serve as a reasonable benchmark to compare MPAS against a variety of world-class methodologies.