GATA1 and myelofibrosis: Deficits in GATA‐1 expression are observed in diverse erythroid diseases, including β‐thalassaemia, MDS, congenital dyserythropoietic anaemia, Diamond‐Blackfan anaemia and myelofibrosis, thus indicating that diverse molecular defects can contribute to GATA‐1 deficiency with important consequences for erythroid differentiation and/or IE.46