CA9 and gastric cancer: To test the correlation between these tissue biomarkers with outcomes in these GC patients, we used Kaplan-Meier survival distributions and log-rank test, based on median IHC expression of positive cell surface percentage (%), as follows: CAIX low group (< 9.9%) and CAIX high group (≥ 9.9%); MVD low group (< 0.6%) and MVD high group (≥ 0.6%); pericyte coverage (ratio between NG2/MVD IHC positive cell surface percentage): low group (< 1.8 median ratios) and high group (≥ 1.8 median ratios).