Method for determining the presence of a number of primary targets of a drug

A method for determining the presence of a number of primary targets of a drug composition in a cell type, said method comprising:

• (a) providing a drug response, said drug response comprising measured amounts of a plurality of cellular constituents in a cell of the cell type at a plurality of levels of exposure of said cell type to the drug composition, by a method comprising measuring said plurality of cellular constituents in a cell of the cell type at a plurality of levels of exposure of said cell type to the drug composition;
• (b) determining an inflection concentration of the drug composition for each cellular constituent in the plurality of cellular constituents, the inflection concentration of the drug composition for a cellular constituent in the plurality of cellular constituents being the level of exposure to the drug composition at which the cellular constituent is increased or decreased in the drug response;
• and
• (c) determining the number of expression sets of cellular constituents, each expression set comprising those cellular constituents with similar inflection concentrations for the drug composition,
• wherein each expression set indicates the presence of a different primary target of the drug composition in the cell type.

A method for determining the presence of a number of primary targets of a change in physical environment of a cell type, said method comprising determining a number of expression sets wherein:

• (a) the expression sets each comprise a plurality of cellular constituents, each cellular constituent in a single expression set having a similar inflection concentration for the change in physical environment;
• (b) the inflection concentration of the change in physical environment for a cellular constituent is the level of the change in physical environment at which the cellular constituent is increased or decreased by the change in physical environment in a response profile;
• and
• (c) the response profile comprises measured amounts of the pluralities of cellular constituents in a cell of the cell type at a plurality of levels of the change in physical environment,
• wherein each expression set indicates the presence of a different primary target of the change in physical environment.