Although an in vivo murine study using systemic administration of the PAI‐1 inhibitor SK‐216 for lung cancer and melanoma indicated that PAI‐1 generated by host rather than tumor cells plays a determinant role in the anticancer effect,31 further accumulation of biomarker data in patients with mRCC treated with axitinib is warranted to verify the results. The gene discussed is SERPINE1; the disease is lung carcinoma.