A major review of autism published recently by the Medical Research Council (MRC) was commissioned by the UK Department of Health in March 2001, partly in response to public concerns raised by research alleging that MMR vaccination might be linked to an apparent increase in the numbers of children with autism. It was designed to be a wide-ranging review of research into different aspects of autism and other autism spectrum disorders (ASDs) — a set of neurodevelopmental disorders which results in impaired ability to communicate and interact with other people. One of the key aims was to identify gaps in knowledge and to make recommendations on future research strategy for the UK. Three groups of scientists examined the research evidence and assessed the strength of research-based knowledge in epidemiology and case definition, physiology and infection, and psychology and behavior. For the first time in an MRC research review there was extensive input from lay people from the outset, putting forward questions that reflected concerns raised by parents of children with autism.