Cover legend: Chili peppers owe their pungency to capsaicinoids, compounds with transient receptor potential vanilloid-1 (TRPV1) agonistic activity. In the photo, a TRPV1 knockout mouse eats a habanero chili (Capsicum chinense), one of the hottest chili peppers, with a reported pungency of up to 300,000 Scoville units. The mouse consumes even the hottest parts of the habanero fruit—the septa and seeds. TRPV1 knockout mice also show locomotor hyperactivity and a predisposition to age-associated obesity. Photography and editing by Andrej A. and Nancy L. Romanovsky. For more information, see the article by Garami et al. in this issue (pages 1721–1733).