Based on the known functions and characteristics of co-expression, the first group of genes is associated with the development of glycolysis and a decrease in mitochondrial metabolism during stage I/II of ccRCC (EGLN3, NDUFA4L2, and CA9), as well as with the activation of proliferation (BHLHE41, IGFBP3, ANGPTL4, and VWF). The gene discussed is CA9; the disease is nonpapillary renal cell carcinoma.