ESR1 and neoplasm: Additionally, we made an unexpected discovery that the GART inhibitor lometrexol is effective only in LumA IDC cells, which mimic both primary and metastatic BC19, while the CHK1 inhibitors AZD7762 and prexasertib lead to ERα degradation and prevent the proliferation of cell lines mimicking the LumA but not the LumB tumor phenotype20.