CXCR4 and cancer: Collectively, the increase in motility-associated integrin subunits and CXCR4 levels in hybrids might equip them with superior migratory potential and help their dissemination to various secondary organs, and therefore explain how fusion could provide a means by which adherent cancer cells acquire new qualities necessary to form metastases (i.e., enhanced motility and matrix degradation) under conditions conducive to hematopoietic survival, and later resume tumor-like activities (i.e., rapid proliferation) under conditions conducive to epithelial survival.