 ANXA1 is lost in clinical breast cancer, indicating that the anti-proliferative protective function of ANXA1 against high levels of estrogen may be lost in breast cancer.This data suggests that ANXA1 may act as a tumor suppressor gene and modulate the proliferative functions of estrogens.Annexin A1 protects against DNA damage induced by heat in breast cancer cells, adding to the evidence that it has tumor suppressive and protective activities.