[Beta-catenin mutations in a common skin cancer: pilomatricoma].

The normal hair development requires WNT signalling pathways. A constitutive activation of beta-catenin, one of the components of this cascade, induces an abnormal proliferation of hair matrix cells. This activation is observed in a human skin tumours called pilomatricoma. Mutations of the beta-catenin gene are detected in 75% of the tumours analysed.