CHDH and pachyonychia congenita: CDH is expressed normally in mesenchymal cells; however, it has a high expression in various tumors, such as gastric cancer, breast tumors, and nasopharyngeal carcinomas (NPC), inducing cancer cells that become more invasive and motile through the suppression of the Akt3 signaling pathway.[40] Therefore, a comprehensive understanding of the pathways can help us to elucidate the crucial mechanism of PC.