In renal carcinoma, NNMT mediates cell invasion and metastasis by activating the PI3K/Akt/SP1/MMP-2 pathway (Tang et al., 2011); however, Yao et al. found that survival rates do not correlate with NNMT expression levels (Yao et al., 2005). This evidence concerns the gene NNMT and renal carcinoma.