EPHA1 and nonpapillary renal cell carcinoma: Other studies using the collected tissue samples for immunohistochemical analysis showed that EphA1 (Wang L. et al., 2015), EphA2 (Wang X. et al., 2015), and VEGFR-1 (Lkhagvadorj et al., 2014) were associated with different pathological stages of ccRCC by directly comparing gene expression differences.