E2F2 and renal cell carcinoma: Construction of a PPI network increases the reliability of our ceRNA network in the following ways: First, some genes described as main hub nodes, such as VEGFA, NTRK2, DLG2, E2F2, MYB and RUNX1, are themselves vital genes in human tumors, and some of them are directly associated with RCC (Chimge et al., 2016; Gao et al., 2016; Gonda & Ramsay, 2016; Jones et al., 2013; Ma et al., 2015; Zubakov, Stupar & Kovacs, 2006).