This continuing series gathers and presents original research results on the leading edge of medicine and biology. Each article has been carefully selected in an attempt to present substantial topical data across a broad spectrum. Topics discussed include the effects of embryo transfer on the phenotype; natural products for the treatment of fungal infections; hepatitis E pathogenesis and prevention; sublingual immunotherapy for allergic rhinitis; childhood tetanus; allergic rhinitis; effects of biologic agents for skin lesions in rheumatoid arthritis patients; electrophysiological studies in multiple sclerosis; ATP as a regulator in the hematopoietic niche and stem cells in ligament repair.