Moreover, altered mRNA metabolism appears to play a pivotal role in blast crisis CML, as mRNA processing, export and translation of specific mRNAs controlling survival and differentiation of myeloid progenitors (e.g. Bcl-XL, GCSFR, C/EBPα and β, MDM2 and MYC) are aberrantly regulated by increased BCR/ABL expression through the activity of specific mRNA binding proteins (e.g. TLS/FUS, hnRNP A1, hnRNP E2, La, hnRNP K and CUGBP1) (Perrotti et al, 1998; Iervolino et al, 2002; Perrotti et al, 2002; Trotta et al, 2003; Guerzoni et al, 2006; Notari et al, 2006). Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.