Our understanding of ALL susceptibility has been informed by genome-wide association studies (GWAS) identifying 11 regions harbouring risk variants: 7p12.2 (IKZF1), 8q24.21, 9p21.3 (CDKN2A/B), 10p12.2 (PIP4K2A), 10q26.13 (LHPP), 12q23.1 (ELK3), 10p14 (GATA3), 10q21.2 (ARID5B), 14q11.2 (CEBPE), 16p13.3 (USP7) and 21q22.2 (ERG)7–16. This evidence concerns the gene ARID5B and acute lymphoblastic leukemia.