Compared to 17 healthy blood (n = 8) or bone marrow (n = 9) donors, we found by qRT-PCR significantly lower median ASPP2 mRNA expression levels in leukemic blasts collected sequentially from 51 consented patients with newly diagnosed acute myeloid or lymphoid leukemia (median normalized expression levels 3.3 vs. 8.8). This evidence concerns the gene TP53BP2 and lymphoid leukemia.