SHMT1 and breast cancer: In BC, Wang et al. (2020) elucidated that activation of autophagy and inhibition of EMT contribute to the treatment of BC, and the mechanism of action of autophagy is expected to be used to improve the treatment of BC (Sun et al.2021).In this study, we found that knocking down SHMT1 could activate the AKT/FOXO3 A signaling pathway and promote BC cell autophagy through the inhibition of ATIC, thereby inhibiting the malignant progression of BC cells in vitro and the growth of BC tumors in nude mice.