To examine the effect of Pra-B on the phosphorylation of EGFR–MEK–ERK pathways of RCC cells, we analyzed the expression of p-EGFR and p-MEK, which are upstream of p-ERK, and the results indicated that their phosphorylation expression was significantly inhibited upon Pra-B treatment 786-O and ACHN cells, not influencing total EGFR/MEK/ERK expression (Figure 4B). This evidence concerns the gene EGFR and renal cell carcinoma.