In BM aspirates with ALL and AML relapse, both PLA2R1 promoter methylation percentages and leukaemic blast cell numbers were strongly elevated in the range of 68.3% ± 6.9% PLA2R1 methylation (p < 0.001 compared to control group) and 87.2% ± 8.7% leukaemic blast cells. Here, PLA2R1 is linked to acute lymphoblastic leukemia.