CA9 and non-small cell lung carcinoma: The prognostic value of CAIX has also been reported in studies of NSCLC.60, 62, 74, 75 HIF1α and HIF2α protein overexpression was shown to have a bad prognostic value in NSCLC, and one meta‐analysis based on 30 studies also showed an association between HIF1α overexpression and lymph node‐positive tumors in NSCLC.59, 61, 62, 74, 76 Finally, CAIX overexpression had a negative impact on prognosis in the present cohort of early stage NSCLC patients.