This review summarizes selected "mechanisms of allergy" articles appearing between 2001 and 2002 in the Journal of Allergy and Clinical Immunology (JACI). Papers chosen include those dealing with human eosinophil and basophil biology from life to death, as well as studies with animal models of allergic disease, including knock-out mice, Brown Norway rats, and ovalbumin (OVA)-sensitized and challenged BALB/c mice, that further our understanding of mechanisms of allergic diseases. When appropriate, articles from other journals have been included to supplement the topics being presented.