The most interesting findings of this study are amplifications of EVX2, HOXD13, HOXD12, HOXD11, HOXD10, and HOXD9 on a 41.6 kb segment of 2q31.1 in all nine mature cystic teratomas (Fig. 2, Table 1, shown red in Fig. 6). Here, HOXD9 is linked to cystic teratoma.