Global histone acetylation levels (histone H3 lysine 9 acetylation [H3K9Ac], histone H3 lysine 18 acetylation [H3K18Ac], total histone H3 acetylation [H3Ac] and total histone H4 acetylation [H4Ac]) were determined in patients with renal cell carcinoma (RCC) using immunohistochemistry in a tissue micro array with 193 RCC and 10 oncocytoma specimens.