ATF3 and colorectal cancer: The involvement of JNK pathway in the regulation of ATF3 activation in various cells is well established [37]–[39], whereas the role of ERK is more controversial; it has been shown to function as a positive regulator of ATF3 in human colorectal cancer cells [40] and negative regulator of TNFα (tumor necrosis factor α) - mediated induction of ATF3 in vascular endothelial cells [38].