Legislation to create a regulatory pathway for follow-on biologics, currently under consideration by the US Congress, raises scientific, regulatory and legal issues. In this month's perspective, Grabowski emphasizes the importance of appropriate data exclusivity periods for new biological entities within this legislation to allow innovator companies to achieve a return on their R&D investments. Meanwhile, our reviews this month cover a diverse range of topics. With the fatty acid-binding proteins emerging as important players in metabolic and inflammatory pathways, Furuhashi and Hotamisligil discuss the therapeutic potential of this protein family, highlighting agents currently in development for the treatment of obesity, diabetes and atherosclerosis. Techniques for imaging atherosclerosis to provide biomarkers of cardiovascular risk have been in the spotlight recently following high-profile clinical trials involving their use. In their Review, Lindsay and Choudhury compare and contrast the ability of current imaging techniques to provide early insights into the therapeutic effects of agents targeting atherosclerosis in clinical trials. They also discuss the evolution of novel functional imaging strategies that are expanding the repertoire of imaging biomarkers. Biomarkers that could help predict the responsiveness of patients with cancer to molecularly targeted therapies are also much sought after. MET tyrosine kinase, which has been linked to cancer initiation and to metastasis, is an attractive target for such therapies, and Comoglio and colleagues provide an overview of the role of MET in cancer and discuss recent progress in the development of therapeutic inhibitors. In our final review, Wafford and Ebert discuss the limitations of current anti-insomnia medications, and describe how recent advances in the understanding of sleep mechanisms is enabling the development of novel therapies that as well as increase overall sleep time, also improve daytime performance.