TNF and breast cancer: In the 10 studies that measured the level of TNF-α, six of them concluded that a lower level of the marker can indicate a better disease prognosis or outcome with treatment (54, 56, 63, 68, 73, 90); while two found no notable changes (70, 88), one showed an increased level of change related to moderate-to-vigorous aerobic exercise (83), and the other found that TNF-α can be a mediator for sleep response following exercise intervention in breast cancer patients (52).