Given the hypothesis-generating nature of this study, we aimed to characterize: 1) the proportion of colon cancer patients with enumerable CTCs prior to exercise training; 2) demographic, clinical, and host factors that correlated with CTCs prior to exercise training; 3) changes in CTCs after exercise training; and 4) the relationship between changes in host factors (i.e., obesity, insulin) with changes in CTCs. The gene discussed is INS; the disease is colonic neoplasm.