BMP4 and breast cancer: Other genes also upregulated by BMP4 that contribute to the formation of hemidesmosomes [17], including integrin β4 (ITGB4) and keratin 14 (KRT14), and a number of chorionic gonadotropin β genes (CGB3/5/7/8) encoding subunits of a hormone that has been implicated in breast cancer progression [18], were also noted.