Acute lymphoblastic leukemia (ALL) is a blood cancer of malignant B lymphocytes (termed B-cell ALL) or T lymphocytes (termed T-cell ALL) that typically occurs in infants and young children. In a three population-representative cohort study, NUTM1 gene rearrangements (i.e. fusion genes) occurred in 0.28 to 0.86% of pediatric patients with B-cell ALL. Among a total of 71 NUTM1-rearranged cases, 10 fusion partners of NUTM1 were identified: ACIN1-NUTM1 (24 cases), BRD9-NUTM1 (10 cases), CUX1-NUTM1 (15 cases), ZNF618-NUTM1 (9 cases; ZNF618 is the zinc finger protein 618 gene) fusion genes, and (in 1 to 4 cases each) AFF1-NUTM1, C17orf78-NUTM1 (C17orf78 is also termed ATAD5), CHD4-NUTM1, RUNX1-NUTM1, IKZF1-NUTM1, and SLC12A6-NUTM1 fusion genes.  Individuals with these NUTM1 fusion gene-associated  leukemias had appreciably better prognoses than those who had NUTM1 fusion gene negative B-cell acute lymphoblastic leukemias. It is thought that the cited fusion genes contribute to the development and/or progression of these NUTM1 fusion gene-associated ALL cases but the molecular mechanism(s) for this is unknown. Some HOXA genes, particularly HOXA9, are upregulated in these NUTM1 fusion gene-associated ALL cases as well as in cases of NUTM1 fusion gene-negative ALL. Further studies are required to determine if the overexpression of one or more HOXA genes contributes to NUTM1 fusion gene-associated B-cell ALL.