The findings indicate that decreasing the levels of GART (phosphoribosylglycinamide formyltransferase, phosphoribosylglycinamide synthetase, phosphoribosylaminoimidazole synthetase), an enzyme that regulates the de novo purine biosynthetic pathway, leads to the degradation of ERα and inhibits the growth of BC cells. Here, GART is linked to breast cancer.