Importantly, this increased migration was prevented by ISO-1 (added directly to CM) or by NAC treatment (added to 66cl4 cells during CM collection, to avoid ROS-mediated secretion) (Figure 4C and Supplementary Figure S3), indicating that autophagy inhibition induced a ROS-mediated secretion of MIF in the 66cl4 cells, which was implicated in the paracrine promotion of malignancy in other breast cancer cells. Here, MIF is linked to breast cancer.