Although serum PAI‐1 and sVEGFRs have been identified as markers of tumor hypoxia, and might be affected by systemic VEGF‐directed inhibitors,28, 32 serum PAI‐1 level may be a more useful prognostic biomarker than serum sVEGFRs in this axitinib study. The gene discussed is SERPINE1; the disease is neoplasm.