ESR1 and cancer: Prescribing recommendations, including FDA labeling in some cases [20], are currently available based on pharmacogenomic results including warfarin (for the biomarkers CYP2D9 and VKORC1) and some cancer treatments that are prescribed to individuals on the basis of specific genetic test findings (e.g. Tamoxifen based on Estrogen receptor biomarker results and trastuzumab based on Her2/neu biomarker results).