However, deletions upstream of SOX9 in patients with 46,XY DSD [8,11-14], as well as duplications upstream of SOX9 in patients with 46,XX DSD [13,15,16,33] do not include TESCO (Figure 3), thus pointing to a second testis-specific enhancer located 517–595 kb upstream of SOX9[13]. Here, SOX9 is linked to disorder of sexual differentiation.