Volume XXV of the Handbook of Experimental Pharmacology series entitled "Bradykinin, Kallidin, and Kallikrein" was published in 1970. My aim in editing this volume of the series is not to replace, but to update the 1970 edition. During the decade preceding the publication of Vol. XXV, the existence of kinins and kallikreins gained acceptance, the protein components of the system were purified and characterized and the peptides were synthesized. Even...