GPX4 and breast cancer: Moreover, a preclinical study has shown that apoptosis-inducing factor mitochondria-associated 2 and GPX4 expression as well as the GSH/GSSG ratio were upregulated after knockdown of the circular RNA glial cell line-derived neurotrophic factor family receptor alpha-1 (circGFRA1), suggesting that circGFRA1 promotes ferroptosis via two independent pathways in breast cancer [75].