ABCB1 and cancer: While we and others have shown that CD44 regulates MDR1 expression in various cancers [49,100,101] and controls COX2-PGE2 signaling in CRC [50,102], whether YB-1 may be linked to the ability of CD44v6 to induce the expression of genes linked to stemness and drug resistance in CD44v6+CICs is not known.