NR4A1 and acute myeloid leukemia: Mullican et al. had reported that there are abnormal phenotypes in Nur77/NOR1 gene double knockout mice (Nur77/NOR1 double −/−): The Nur77/NOR1 double −/− mice have a smaller body shape, and most of them died between 3 and 4 weeks after birth, which may be due to the development of a symptom and disease similar to human acute myeloid leukemia (AML), a hematological malignant tumor that can cause a high mortality rate (Mullican et al., 2007).