Case-control comparisons of overall association of variation within each haplotype block between case groups and controls (1000 permutations) revealed significant differences for BCP-ALL in Block 1 (P = 0.002) and T-ALL in Block 4 (P = 0.049), but no global difference in haplotype frequencies between either case group and controls for haplotype blocks 2 or 3 (P>0.097) (Table 1). Here, OPN1SW is linked to acute lymphoblastic leukemia.