are discussed in dillon amp goldstein multivariate analysis methods and applications john wiley amp sons new york 1984 and duda hart amp stork pattern classification 2d ed john wiley amp sons new york 2000 each of which is incorporated herein by reference in its entirety performance of the function can be evaluated by various statistical methods the output of such a method is metabolites that can serve as biomarkers including efficacy biomarkers surrogate biomarkers and toxicity biomarkers the metabolites are detected using analytical chemistry techniques including mass spectrometry in one embodiment the metabolites are detected using gas chromatograph mass spectrometry gc ms in one embodiment the metabolites are detected using liquid chromatograph mass spectrometry lc ms gc ms techniques are known in the art including without limitation quadrupole gc ms ion trap gc ms time of flight gc ms sector gc ms etc lc ms techniques are known in the art including without limitation quadrupole triple lc ms quadrupole lc ms 3d ion trap lc ms linear iontrap lc ms time offlight lc ms quadrupole time offlight lc ms hybrid lc ms sector lc ms ft icr lc ms etc maldi tof ms techniques are known in the art including without limitation linear only maldi tof ms linear and or reflectron maldi tof ms tof tof maldi tof ms etc such techniques are reviewed in.