FR-α is a glycosyl phosphatidyl inositol (GPI)-linked protein which is present in the apical region of normal cells which is not exposed to the blood circulation, whereas in case of cancer cells, it is exposed to the blood circulation and therefore, folate-conjugated nanoparticles internalized with high affinity (receptor-mediated endocytosis) [24, 25]. This evidence concerns the gene FOLR1 and cancer.