This inhibition probably initiates with the up-regulation of miR-26b-5p and the decreased expression of SMAD-4 and is followed by the down-modulation of p21−Cip1 and up-regulation of c-Myc genes, which finally allows for restarting of the cell cycle in CLL cells. Here, CDKN1A is linked to B-cell chronic lymphocytic leukemia.