MUC1 and pachyonychia congenita: The results showed that MUC1 expression significantly associates with decreases in PSA/KLK3 (Fig. 8d) and increases in BRN2 (Fig. 8e), providing support for the central premise that MUC1-C is upregulated in PC progression in association with downregulation of AR signaling and induction of the BRN2 pathway.