HOXD9 and nonpapillary renal cell carcinoma: Subsequently, we built a prognostic signature based on eight HOX genes including HOXB1, HOXA7, HOXB5, HOXD8, HOXD9, HOXB9, HOXA9, and HOXA11 in ccRCC for risk stratification, which allowed patients with higher or lower risk score to be divided into different risk groups.