The inhibition of NF-κB, a transcription factor associated with adhesion molecule signaling and in fact necessary for B-ALL cell binding to MSC, as shown here, was not able to induce sensitization to DEXA or VINC, and therefore seems not to be the exclusive molecular connection through which stromal PKC protects B-ALL cells. Here, NFKB1 is linked to precursor B-cell acute lymphoblastic leukemia.