IGFBP6 and breast cancer: Interestingly, compared to the control untreated cells, the breast cancer cells reacted to 24 h of IGFBP6 exposure by inducing significant up-regulation of antioxidant-related genes, such as heme oxygenase 1 (HMOX1; Figure 5A), glutathione S-transferase kappa 1 (GSTK1; Figure 5B), and NAD(P)H dehydrogenase (quinone) 1 (NQ01; Figure 5C).