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Abstract Cell‐based assays in GPCR drug discovery Siehler, S., Biotechnol. J. 2008, 3, 471‐483 G protein‐coupled receptors (GPCRs) transmit extracellular signals into the intracellular space. They play key roles in the physiological regulation of virtually every cell and tissue and are a major class of drug targets. Sandra Siehler (Novartis Institutes for BioMedical Research, Basel, Switzerland) reviews cell‐based assays for screening GPCR drugs. In the past receptor binding assays comprised the main readout for receptor activity but these approaches are now complemented by measurement of the intracellular responses to receptor activation. This allows for better discrimination of agonism and antagonism and investigation of those receptors for which labeled ligands are not readily available. The sheer number of assay readouts for these receptors highlights how basic biological knowledge intertwines with drug discovery and characterization. Label‐free cell‐based assays for drug discovery Xi, B. et al.: Biotechnol. J. 2008, 3, 484‐495 Cell‐based assays are an important part of the drug discovery process. Conventional label and reporter‐based cell assays may be more prone to artifacts due to considerable manipulation of the cell either by labeling or overexpression of targets or reporter proteins. Cell‐based label‐free technologies preclude the need for cellular labeling or over expression of reporter proteins, utilizing the inherent morphological and adhesive characteristics of the cell as a physiologically relevant and quantitative readout for various cellular assays. Furthermore, these technologies utilize non‐invasive measurements allowing for time resolution and kinetics in the assay. In this article, researchers from San Diego (CA, USA) review the various label‐free technologies that are being used in drug discovery settings. Computational chemistry approaches to drug discovery Fischer, P. M., Biotechnol. J. 2008, 3, 452‐470 Whilst cell based functional screening constitutes an important approach in drug discovery, the availability of detailed structural information on many drugs targets has given impetus to approaches that use the structure of the target under investigation as a guiding principal. Computational techniques help predicting binding activity of chemical structures and they are widely used as components of the drug discovery screening cascade including discovery in the area of signal transduction. In this Review Peter Fischer (Nottingham, UK) introduces the enormous range of computational techniques currently available to aid the drug discovery process and describes their different rationales and underlying principles.