FOLR2 and cancer: To more precisely characterize the specific cells that carry the FR-α and FR-β antigens, each FR+ and FR− staining cell was carefully scrutinized for its specific cell type and location, and then categorized as either a cancer cell, macrophage-like cell located within the tumor margin, macrophage-like cell located outside the tumor margin, or other normal cell (endothelial cell, fibroblast, etc.).