Furthermore, our results suggest that NNMT expression decreases the inhibition of cell viability and ATP production and the increase in ROS production induced by oxidative stress and demonstrated that NNMT and its product 1MNA negatively regulate autophagy to protect breast cancer cells against oxidative stress by suppressing the activation of the AMPK-ULK1 pathway, these findings may provide a novel strategy of targeting NNMT for the combined treatment of breast cancer. This evidence concerns the gene ULK1 and breast cancer.