PECAM1 and neoplasm: Mice allocated to a voluntary exercise condition were compared to a control group (n = 11–12 per group) and it was shown that the exercise group had a significantly lower tumor growth rate (P < 0.012), higher tumor apoptosis (P = 0.048), greater microvessel density (P = 0.004) and increased tumor vessel maturity, as determined by colocalization of CD31 with desmin (281).