p-ERK-mediated ATF4 activation can also protect pancreatic cancer cells from ferroptosis (Dixon et al., 2014), and evidence shows that cystine starvation can increase the phosphorylation of eIF2α, as well as the expression of ATF4, in human triple negative breast cancer (TNBC) cells, resulting in ferroptosis (Chen et al., 2017). This evidence concerns the gene ATF4 and triple-negative breast carcinoma.