We investigated the tumor-suppressor gene, TP53, in psoriatic skin at gene (GP53) and protein (p53) levels. No mutation was detected in the seven exons analyzed using a combination of polymerase chain reaction and single-strand conformation polymorphism techniques. In addition, by immunohistochemistry using three different anti-p53 antibodies, no positive staining, reported to be associated with mutations and/or abnormal expression of the TP53 gene, was observed in psoriatic skin biopsies, in contrast to recent reports. These results suggest that the proliferative status of psoriatic keratinocytes does not implicate the TP53 gene.