ATF4 and cancer: ATF4, a transcriptional master regulator of AA metabolism and stress responses (Fig. 3), can upregulate AA metabolism including AA synthetases (including asparagine and serine), transporters (such as glutamine) and sensors for cancer cell proliferation via the cooperation of KDM4C-mediated H3K9 demethylation and ATF4-mediated transactivation [74, 75].