STAT3 and nonpapillary renal cell carcinoma: To elucidate the underlying mechanism of the distinct inhibition of ccRCC cells induced by CVB, The levels of total and phosphorylated AKT, STAT3 and the major members of the MAPK family (JNK, P38 and ERK) were detected using Western blot analysis to elucidate the mechanism underlying the distinct CVB-induced inhibition of ccRCC cell activity.