In this issue of the ARCHIVES, Nguyen and colleagues present a clinically oriented study of 24 consecutive patients with Proteus syndrome who were evaluated at the National Institutes of Health in Bethesda, Md.1 The diagnostic criteria of Proteus syndrome proposed by an international working group some years ago were met in all cases.2 Because this multisystem birth defect occurs rarely, an analysis of such a large cohort is most welcome.