Although a previous study showed that fused NUP98 proteins, i.e., NUP98-HOXA9 and NUP98-PMX1, interact with HDAC1 and are involved in the regulation of genes implicated in acute leukemia (46), our experiments with transiently expressed NUP98 indicate that unfused NUP98 might not interact with HDAC1. This evidence concerns the gene HOXA9 and acute leukemia.