In Brief

The study examined the expression patterns of hair keratins in pilomatricomas, benign skin tumors originating from hair follicle cells. It was found that the co-expression of hair keratin hHa5 and the regulatory protein HOXC13 was maintained in the lower transitional cells of these tumors. However, the expected nuclear co-expression of LEF1 and β-catenin, which is crucial for cortex cell differentiation in normal hair follicles, was absent in the upper transitional cells of pilomatricomas. Instead, this co-expression was found in a subset of hair keratin-free basaloid cells. This suggested that cortical differentiation in pilomatricomas did not follow the canonical Wnt signaling pathway, unlike in normal hair follicles.