In a study on the NCI-H157 human lung cancer cells, Park et al. [37] showed that combination of ATO (2.5 μM) and sulindac (5 μM) increased apoptosis, reactive oxygen species (ROS), and oxidative stress, as evidenced by the heme oxygenase-1 (HO-1) expression and phosphorylation of ERK. This evidence concerns the gene HMOX1 and lung cancer.