Within a biological system such as a cell or tissue, water structure and dynamics are known to be changed by the presence of biomolecules or extrinsic entities (e.g. drugs), while in turn water is prone to disturb the conformational behaviour and function of biomolecules. Disruption of the coherent structure of cellular water by even very subtle stimuli is expected to have a significant cost at the functional level, and may even induce pathology.The present study aims at extending this concept to the activity of pharmacological agents. The INS technique will be used to probe the effect of an anticancer drug (cisplatin) on intracellular water structure in human cancer cells.This is an innovative way of tackling the drug´s pharmacodynamics leading to an improved understanding of its in vivo mode of action.