For instance, it has been shown that ATF2 knockout might lead to tumor suppression or promotion depending on the model of mice used in the experiment.19 Its roles also include the regulation of several genes responsible for cell multiplication, apoptosis, transformation, and inflammation.16 These genes include MMP-2 and MMP-9 in MCF10A breast epithelial cells, in which ATF2 induces their migration and promotes their invasiveness. This evidence concerns the gene ATF2 and neoplasm.