CXCR4 and skin basal cell carcinoma: The expression of CXCR4 in bone marrow cells was decreased from 80.3% to 10.4% (Figure 4C,E) in BCC‐Ex treatment group compared with control group, whereas MDSCs (CD11b+Gr1+) were increased from 45.2% to 92.4% (Figure 4D,F).