Moreover, cancer cells have been found to home in on tissues with high levels of CXCL12 expression (Xue et al., 2017) and to increase their own secretion of CXCL12 to attract CXCR4-expressing stromal cells that can, in turn, assist with tumor development (Guo et al., 2016). The gene discussed is CXCR4; the disease is cancer.