CXCR4 and Waldenstrom macroglobulinemia: The effect of targeting CXCR4 on the TME is also currently being investigated in renal cell carcinoma, Waldenström macroglobulinaemia, and melanoma, upon combined treatment with the allosteric CXCR4 modulator Mavorixafor and anti-PD1 immune checkpoint blockade (ClinicalTrials.gov: NCT04274738).