The folate receptor (FR) family consists of 4 isoforms, includingFRα, FRβ, FRγ, and FRδ.14,15 These receptors differ in tissue/cell-specific distribution andfolate binding capacity.16 FRα isspecifically expressed in tumor cells of epithelial origin,17−19 whereas FRβ is frequently expressed in macrophages. This evidence concerns the gene FOLR2 and neoplasm.