Folate Receptor 1, Adult (FOLR1) is a member of the folate receptor family, which includes FOLR1, FOLR2, and FOLR3. These receptors are glycosylphosphatidylinositol (GPI)-linked cell surface glycoproteins that bind to folate with high affinity. FOLR1 is predominantly expressed in adult tissues, particularly in the epithelial cells of the lung, placenta, and kidney. It plays a critical role in the uptake of folate, which is essential for DNA synthesis and cell growth. FOLR1 is also a target for certain types of cancer therapy, as some tumors overexpress this receptor, making it a potential biomarker for targeted drug delivery systems.Besides,Epithelial Cell Adhesion Molecule (EPCAM) has been identified as an interactor of 去, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human FOLR1 and recombinant human EPCAM. Briefly, FOLR1 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to EPCAM-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-FOLR1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 μL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant human FOLR1 and recombinant huma EPCAM was shown in Figure 1, the EC50?for this effect is 7.36ug/mL.