Thinking about how asthma and allergic diseases arise is undergoing several shifts. In ‘Bedside to Bench’, Clare M. Lloyd and Sejal Saglani examine how recent human studies are putting the focus on the epithelium as a major contributor to asthma. The findings shift the emphasis away from the T helper type 2 immune response, and call into question the utility of current animal models of the disease. Although asthma and other allergic disorders are known to have origins in infancy, some researchers are looking even earlier, to effects in utero and before conception. In ‘Bench to Bedside’, Catherine Hawrylowicz and Kimuli Ryanna highlight animal studies that outline some of the effects of the maternal environment, and they examine the potential implications for prevention of disease.