Specifically, the mRNA export activity of hnRNP A1, an RNA-binding protein overexpressed in CML-BC, is required for cytokine-independent proliferation, survival and tumorigenesis of acute phase CML blasts and BCR/ABL-expressing myeloid progenitor cell lines (Iervolino et al, 2002). Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.