To address this issue, we developed a scale from 1 to 3 (1 corresponding to poor and 3 to good morphology; Fig. 7) for scoring chromosome morphology (chromosome morphology score; CMS) in a consistent manner and applied it to 37 cases of high hyperdiploid ALL and 33 cases of ETV6/RUNX1-positive ALL. Here, ETV6 is linked to acute lymphoblastic leukemia.