CD44 is a cell surface adhesion molecule that mediates cell‐cell and cell‐extracellular matrix (ECM) interactions by binding to hyaluronic acid (HA), whilst CD24 is a small sugar involved in the negative regulation of chemokine receptor CXCR4 protein activity in mediating breast cancer metastasis.4, 10, 18, 19. The gene discussed is CXCR4; the disease is breast carcinoma.