We would like to comment on the article by Kress et al1 in a recent issue of the Archives that described, for the first time, an abnormality in keratin expression in a patient with Olmsted syndrome. The authors state that "AE1 is a monoclonal antikeratin antibody that has specificity for the acidic keratins, including keratins 5 and 14." Keratin 5 is a basic keratin that binds to the acidic keratin 14; therefore, keratin 5 should not directly interact with AE1.2,3 The AE1 immunostaining pattern seen in Figure 5 in the article by Kress et al1 may be ascribed to the presence of any of the acidic keratins, theoretically with or without their physiologically associated basic keratins.3 Although the decreased basilar AE1 staining suggests that there is defective processing and/or expression of keratin 14 in the basal keratinocytes, it provides no direct evidence for the presence of