SPDEF and pachyonychia congenita: HOXB13 is able to interact with different molecular pathways during PC evolution: (i) suppresses Prostate Derived ETS Factor (PDEF) [93]; (ii) suppresses p21 in castration-resistant PC, stressing this important step in PC cell survival under no androgen-influence [94]; (iii) promotes PC cell invasion and metastasis by decreasing intracellular zinc levels, enhancing NF-kB [95].