KDR and nonpapillary renal cell carcinoma: Moreover, according to GSEA enrichment analysis results, genes in the A2M high expression group of ccRCC patients were mainly positively correlated with lymphatic angiogenesis, angiogenesis, VEGF, and VEGFR signaling pathways, and negatively correlated with signaling pathways such as reproduction, DNA methylation, and linoleic acid metabolism (Figure 4F & Table S7&8).