Recent findings have suggested that AEG-1/MTDH is overexpressed in PC cells and that cryptotanshinone exerts antitumor activity via inhibition of hypoxia inducible factor 1α, AEG-1/MTDH and vascular endothelial growth factor in hypoxic PC-3 cells (67). Here, MTDH is linked to pachyonychia congenita.