CXCR4 and skin basal cell carcinoma: Flow cytometry results showed that there were a high expression of CXCR4 (65.8%, Figure 4A) and a low expression of CX3CR1 (18.8%, Figure 4B) in bone marrow cells, suggesting that CXCR4 might be responsible for the differentiation of bone marrow cells into MDSCs induced by BCC‐Ex.