CXCR4 and neoplasm: However, in vivo growth of CXCL13-silenced MM cells was significantly suppressed, reflected by decreased tumor burden in the BM of mice injected with RPMI8226-CXCR4-GFP CRISPR-CXCL13 in comparison with the parental RPMI8226-CXCR4-GFP cells (Fig. 6F).