IKZF3 and acute lymphoblastic leukemia: Because IKZF1 also contains ALL risk alleles identified in previous GWAS, we tested for the presence of statistical interaction between our top genotyped SNP in IKZF1 (rs11978267; PCCRLP = 2.15 × 10−29) and our top genotyped SNP in IKZF3. We detected no significant epistatic effect in either case–control analyses (P = 0.62) or case-only analyses (P = 0.16).