Because of the role of Twist1 in macrophage recruitment to tumor tissues and the role of tumor-associated macrophages (TAMs) in cancer progression and metastasis by stimulating tumor growth, angiogenesis, and cellular invasion, migration and EMT induction, we selected Twist1 and examined its cytoplasmic and nuclear expression in the same set of RCC tissues, by immunohistochemistry on a tissue microarray. The gene discussed is TWIST1; the disease is cancer.