The ESR1 reference set 1% AF cfDNA is specifically developed as a quality control material for both lab-developed tests (LDTs) and CE-IVD labeled assays, focusing on ESR1 mutations in cell-free DNA (cfDNA). This set provides a reliable standard for ensuring accuracy in ESR1 mutation assays. The selection of mutations was thoroughly reviewed and endorsed by leading experts in the field, along with developers of ESR1 testing protocols, ensuring its relevance and quality.

ESR1 mutations have been reported in approximately 11%–55% of estrogen receptor-positive metastatic breast cancer patients treated with aromatase inhibitors, according to several retrospective cohort studies. The ESR1 reference set supports laboratories in validating their assays at the cfDNA level, helping to maintain consistency and reliability in ESR1 mutation testing.