HIF1A and nonpapillary renal cell carcinoma: VEGF protein, a target gene for both HIF-1 and HIF-2, was found to be expressed at lower levels than in cortex tissue in all grades of pRCC (Figure 2E) while in ccRCC, levels were only decreased in lower grade tumors compared to matched renal cortex tissue and increased in the tumors with increasing grade (p < 0.05; Figure 2F).