CXCR4 and neoplasm: Since then, further in vitro and in vivo studies have alsoshown its direct antitumor activity when given in combination withthe anti-CD20 monoclonal antibody rituximab.16 The in vitro inhibition of CXCR4 induced by plerixaforin human Raji and B104 DLBCL-lymphoma cell lines led to the suppressionof tumor-promoting signals delivered by the CXCR4/CXCL12 axis.