Fig. 3. Clinical appearance and pathohistology of various human desmosomal disorders. Pemphigus vulgaris (A and B) is characterized by the loss of intercellular adhesion between basal and suprabasal keratinocytes (A) and by skin blistering and erosions (B). The hallmark of palmoplantar keratoderma (C and D) is massive thickening of the stratum corneum (C), resulting in dramatically thickened skin on palms and soles (D). Arrhythmogenic right-ventricular cardiomyopathy (ARVC) is characterized by fibrofatty replacement (^*) of the myocardium (E). Please refer to Table 1 for additional information on specific molecular targets of each disease. Panel D is reprinted from (Rickman et al., 1999) with permission from Oxford University Press. Panel E is reprinted from (Protonotarios and Tsatsopoulou, 2004) with permission from Elsevier.