There are only few studies testing in vitro efficacy of L-Asp in AML, showing sensitivity to L-Asp in some FAB subgroups, including M1 (Acute myeloblastic leukemia with minimal maturation), M4 (Acute myelomonocytic leukemia) and in particular in the M5 subgroup (Acute monocytic leukemia), that showed low expression of ASNS [24–26]. The gene discussed is ASNS; the disease is acute myelomonocytic leukemia M4.