Analysis of ANGPTL4 mRNA production in various types of tumor. a–d: Bright-field (left) and dark-field (right) views of ANGPTL4 mRNA production in necrotic areas of a pulmonary carcinoma (a), renal oncocytoma (b), chromophobic RCC (c), and in conventional RCC (d). e: Production of ANGPTL4 mRNA by tumor cells of conventional RCC. f: Northern blot analysis of ANGPTL4 mRNA levels in normal kidney and conventional RCC. T, tumor tissue; N, necrotic area; C, kidney capsule. Scale bars, 100 μm.