When the c-Met+ and CXCR4+ cell counts in breast cancer were calculated according to the clinicopathology of these patients (Table S1), the numbers of HGF+, c-Met+ or CXCR4+ cells increased along with the histopathological grading of the tumor (P<0.001) (Figure 1B, Table S1). The gene discussed is HGF; the disease is breast cancer.