As MYC expression can also be significantly influenced by the interaction of estrogen receptor alpha (ERα) with ERBB2, and as MYC-associated glutamine dependence has been linked to aromatase inhibitor (AI) resistance in ER+ breast cancer, fulvestrant - an ERα downregulator that also inhibits MYC expression and glutaminase - has been suggested as a therapeutic agent in AI-resistant ER+ breast tumors [82] and may experience future repurposing for further indications (Figure 4, upper right corner). Here, ESR1 is linked to breast cancer.