CTNNB1 and pilomatrixoma: A mutation within the hair follicular matrix cells is the source of pilomatrixoma.25 It is postulated that the development of pilomatrixoma involves the Wnt signalling pathway.25 The oncogene BCL-2, which represses apoptosis processes, has been implicated in pilomatrixoma.26 Furthermore, CTNNB1, causing LEF-1 or B-catenin dysregulation, has also been implicated.27