COL4A1 and clear cell renal carcinoma: Through PPI network construction, key hub genes were identified, including COL1A1, COL1A2, COL5A1, POSTN, COL4A1, COL4A2, LAMA4, COL11A1, COL8A1, and COL15A1, which had a completely positive correlation with EOGT. Interestingly, some researches have shown that COL1A2, COL1A1, COL5A1, and POSTN were identified to be involved in TMB and immune infiltration, which were linked to poor outcomes of clear cell renal cell carcinoma (20).