Identify the molecular targets and mechanism of action of a lead compound that come out of a cell-based screening to facilitate the further improvement the efficiency and toxicity profile of the lead.

Validating a lead compound from a target-based screening by confirming the target used in in vitro screening is the true and the major target in vivo.

Identify some "off-target" protein that interacts with a lead compound, which lead to cardio-toxicity or heptotoxicity.

Searching other therapeutic applications of a drug molecule.