For this purpose, a previously characterized [32, 33] human anti-human FR-β mAb (m909) that can bind either M1- or M2-FR-β-expressing macrophages [14, 15, 18] was initially utilized to stain tissues from three accessible inflammatory diseases via skin biopsy, namely, psoriasis, scleroderma, and sarcoidosis. Here, FOLR2 is linked to sarcoidosis.