HOXC6 and pachyonychia congenita: The homeobox cluster included genes such as HOXC6 and DLX1 which are included in the SelectMDx® urine-based test for detection of high-risk PC [32], as well as EN2, GLI3, and MEIS2 previously investigated for their biomarker potential and/or function in PC [18, 33, 34].