PTEN and neoplasm: Since a 10–60 fold-increase in miR-155 expression has been identified in aggressive DLBCL [71] and expression of this miRNA in NK-cell lymphomas has been associated with decreased levels of SHIP, PTEN, and PDCD4, all of which are tumour suppressors, suggesting that inhibition of miR-155 in this T-cell lymphoma drives tumourigenesis [72].