FN1 and leukemia: The expression of the dominant-negative Ikaros isoform IK6 in the T-ALL (Jurkat) and B-ALL cell lines (RS4;11, Nalm6) lifted the transcription suppression of FUT4, which fucosylates α5β1 on leukemia cells and tightens the adhesion of ALL cells to fibronectin in the ECM.