LEP and neoplasm: Potential mechanisms could be an exercise-mediated; (1) increase in peripheral lymphocyte proliferation as suggested by Dos Santos et al.32, (2) reduction in serum leptin levels, which may be mediating a link between obesity, T cell dysfunction, and enhanced tumor growth31, (3) reduction in the chronic low-grade inflammatory state that is often associated with obesity32, and lastly (4) reduction in the availability of the nutrients needed for tumor growth33,34.