When Mindbomb-1 (Mib1), an essential gene for Notch ligand endocytosis, was deleted (Mx1-cre; Mib1−/− mice or MMTV-cre, Mib1−/−1 mice), the mice developed de novo myeloproliferative neoplasm (MPN), which is attributable to the loss of Mib1 from the bone marrow microenvironment (Kim et al., 2008). Here, MIB1 is linked to myeloproliferative disorder.