ABI1 and myeloproliferative disorder: Although disruption of mammalian Abi1 has been implicated in the pathogenesis of myeloproliferative neoplasm and acute myeloid leukemia (Chorzalska et al., 2018; Morerio et al., 2002; Shibuya et al., 2001; Taki et al., 1998), it is unknown how actin-regulatory Abi proteins regulate normal hematopoiesis.