There was no significant difference in the expression of ERK1/2 protein among negative control, normal control and siRNA groups, but the expression of p-ERK1/2 in the siRNA group was significantly lower than that in the control group, indicating that inhibition of the proliferation, invasion and migration of prostate cancer cells through downregulating Arf6 expression may be related to the downregulation of p-ERK expression. This evidence concerns the gene MAPK3 and prostate cancer.