In the future, follow up studies on the molecular basis for the differential effects of rest and exercise serum on prostate cancer cell growth are highly motivated, preliminary data suggest that compensating for the lower levels of EGF in the post exercise serum by adding rhEGF partly reverse the growth inhibitory effect of exercise serum (data not shown), thereby supporting the idea that multiple factors altered by exercise are involved. Here, EGF is linked to Familial prostate cancer.