CA9 and neoplasm: The tumor size (median, 3 cm; P = 0.88), age (P = 0.36), the mitotic activity index (P = 0.09), the microvessel counts (hot-spot P = 0.54; global P = 0.25), the margin status (P = 0.23), the VEGF expression (stromal P = 0.96; epithelial P = 0.11), the CAIX expression (stromal P = 0.46; epithelial P = 0.16) and the epithelial HIF-1α expression (P = 0.76) were not of prognostic relevance.