KIR3DL1 and acute lymphoblastic leukemia: In contrast to ALL and AML, the strength of protection from developing CML offered by the KIR AA genotype was enhanced by the C2 ligand (OR = 0.34, 95% CI = 0.18–0.65, Pc = 0.004) to a much greater degree than by the C1/Bw4 ligands (Figure 2C).