Four years ago, two anticancer drugs that target tumour angiogenesis — the establishment of a blood-vessel network essential for tumour growth — became the focus of worldwide attention after a controversial front-page article in the New York Times. Although the drugs in question, endostatin and angiostatin, still hold much promise, there have been several prominent late-stage failures for other anti-angiogenic drugs, which might, in part, be because traditional clinical-trial designs are not appropriate for these novel agents. In our lead Review, Cristofanilli and colleagues consider clinical strategies to exploit the potential of anti-angiogenic drugs, which is complemented by this month's From the Analyst's Couch article about the market for drugs that target angiogenesis. Some of the most promising anti-angiogenic drugs are biotechnological products, and issues related to the immunological properties of biotech drugs in general are the focus of two articles. Cavagnaro's Perspective discusses the challenges inherent in their preclinical safety evaluation, in particular owing to interspecies variation, and Schellekens' Review highlights the issues that surround the production of generic versions of biotech drugs, which have immunogenic properties that depend on the production process. Two Reviews consider novel therapeutic approaches to disease states: Barnes' article focuses on chronic obstructive pulmonary disease, for which there is a pressing need for drugs to reduce disease progression, and Raymond and Satelle highlight the potential of ligand-gated chloride channels as targets for antiparasitic drugs. The Reviews section is completed by Braeckmans and colleagues' article on encoding strategies for microcarriers used in combinatorial synthesis, drug screening and diagnostic applications, and in the lead Perspective, Lindpaintner considers the impact of pharmacogenetics and pharmacogenomics on drug discovery.