The physiological stimuli driving amoeboid motility in cancer cells both in vitro and in vivo have yet to be identified; however, CXCL12 supports blebbing and amoeboid motility [29], [38] and CXCL12 is highly expressed in tissues that are prevalent sites of distant breast cancer metastasis [39], [40]. Here, CXCL12 is linked to cancer.