TargetMol offers a high quality Target-focused Phenotypic Screening Library (1796 compounds in total) with maximal biological and chemical diversity for such empirical approaches. Phenotypic approaches use semi-empirical methods that do not require much knowledge of the target and understanding of the mechanism. A recent analysis revealed the phenotypic approaches to be the more successful strategy for small-molecule, first-in-class medicines. The rationalization for this success was the unbiased identification of the molecular mechanism of action (MMOA). In addition, an understanding of mechanism is not required for regulatory approval; the regulatory agencies are less concerned with the MMOA of a compound than with whether it is effective. It can be argued that in seeking the best path to new medicines, academic science should be focusing not on gene-based, hypothesis-driven research but on translating disease knowledge into disease-relevant phenotypic assays for screening and chemical biology approaches to screening and target identification as well as on systematic approaches to understanding the MMOA. Greater focus on translational research should lead to greater access to more reliable phenotypic assays.

Use of well-annotated bioactive compounds with clear targets for phenotypic screening can also narrow the scope of targets that are needed to be validated, therefore, it is an effective tool for target identification or validation.

Given the potential applications of a Phenotypic Screening Library, the focus of the compounds selection strategy lies on biodiversity and maximal coverage of chemical space, aimed at providing hits for a wide spectrum of biological goals. This library finally was developed to contain a set of compounds with confirmed biological activity for more than 600 drug targets and includes 2-4 structurally diverse compounds for each target.