HOXA9 and astrocytoma (excluding glioblastoma): Another study in 37 cases of spinal ependymoma and 12 cases of astrocytoma showed that while both HOXB13 and the other HOX family member HOXA9 were selectively expressed in SP-EPN instead of astrocytoma, only HOXB13 was expressed exclusively in MPE, whereas HOXA9 was detected in all subgroups of SP-EPN [12].