To gain insight into the pathobiological involvement of PAK4 in PC, we silenced its expression in two high PAK4 expressing, tumorigenic and aggressive cell lines, MiaPaCa and T3M4, by stable transfection of PAK4-targeted shRNA (shPAK4) or non-targeted scrambled sequence (NTScr) expression constructs. This evidence concerns the gene PAK4 and pachyonychia congenita.