Description_x000D_ General description_x000D_ Folate receptor β, also known as Folate receptor 2, FBP, FOLR2, β-HFR, FBP/PL-1, FR-β, FR-P3, and is a member of the folate receptor (FOLR) family which mediates delivery of 5-methyltetrahydrofolate to the interior of cells. This protein has a 68% and 79% sequence homology with the FOLR1 and FOLR3 proteins, respectively. The FOLR2 protein was originally thought to exist only in placenta, but is also detected in spleen, bone marrow, and thymus. FOLR2 is predominantly expressed in placenta, cells of the neutrophilic lineage, and some CD34+ hematopoietic progenitor cells. It is upregulated on myeloid leukemias, head and neck squamous cell carcinomas, and several nonepithelial cancers. It is also upregulated on macrophages and monocytes at chronic inflammatory sites including rheumatoid arthritis synovium and glioblastoma. FOLR2 is a marker for macrophages generated in the presence of M-CSF, but not GM-CSF. Its expression correlates with increased folate uptake ability. Folate conjugates of therapeutic drugs are a potential immunotherapy tool to target tumor-associated macrophages._x000D_ Physical form_x000D_ Lyophilized from 0.22 μm filtered solution in PBS, pH 7.4. Normally Mannitol or Trehalose is added as protectants before lyophilization._x000D_ Reconstitution_x000D_ Centrifuge the vial prior to opening. Reconstitute in sterile PBS, pH 7.4 to a concentration of 50 μg/mL. Do not vortex. This solution can be stored at 2-8°C for up to 1 month. For extended storage, it is recommended to store at -20°C.