CXCR4 and neoplasm: Tumour cells expressing the receptor for CXCL12 (CXCR4), which is involved in metastasis,53 were strongly reduced (Figure 8A), reflecting the effect of hypoxia on tumour cells,54 whereas CXCR4 expression was not affected in CD45+ cells (Figure 8C) or in the endothelial cell‐enriched population (Figure 8D).