ABCC1 and acute myeloid leukemia: Table 2 shows the mean difference between normal and AML samples and their p-values. Although no significant difference was observed between NR and Relapsed patients (p = 0.171), the MRP1 expression level in both groups was meaningfully (p < 0.005) different from the Healthy or CR groups and there appeared to be a tendency towards higher MRP1 expression at the time of relapse.