FITC Rat Anti-Mouse FR4 Antibody (S-R705)

Folate receptor 4 (FR4), also known as folate receptor delta or IZUMO1R, is a protein encoded by the FOLR4 gene in humans. It is a subtype of the receptor for the vitamin folic acid and is primarily expressed on CD4 T lymphocytes, with lower expression on CD8 T cells. FR4 is highly expressed in regulatory T cells (Tregs) and is also found in tumor-associated macrophages (TAMs) and T follicular helper cells (TFH cells). This protein plays a role in immune regulation, as its high expression can distinguish Tregs from other T cells. Additionally, FR4 is involved in the high-affinity binding and transport of folate and folate analogs across the cell membrane.