METHOD FOR DETERMINING THE PRESENCE OF A NUMBER OF PRIMARY TARGETS OF A DRUG

This invention relates to methods and systems for characterizing the actions of drugs in cells. In particular, the invention provides methods for determining the presence of a number of primary targets through which a drug, drug candidate, or other compound of interest acts on a cell. Thus, the invention also relates to methods for drug development based on the disclosed methods for determining the presence of a number of primary targets of a drug. The methods of the invention involve: (i) measuring responses of cellular constituents to graded exposures of the cell to a drug of interest; (ii) identifying an "inflection concentration" of the drug for each cellular constituent measured; and (iii) identifying "expression sets" of cellular constituents from the distribution of the inflection drug concentrations. Each expression set corresponds to a particular primary target of the drug. The invention also provides computer systems which determine the presence of a number of targets of a drug by executing the disclosed methods.