CXCR4 and B-cell chronic lymphocytic leukemia: In CLL, several clinical trials combined a CXCR4 antagonist with conventional cytotoxic agents (i.e., bendamustine, fludarabine, cyclophosphamide, and lenalidomide) or mAbs (i.e., rituximab and alemtuzumab) [233,240,241,242].