IGFBP3 and viral infectious disease: FCG2B, IGFBP3, CAH6, and ASGR1 are druggable targets.28 FCG2B is a receptor for the Fc region of IgG; it modulates antibody complex processing by B cells, and its function has been researched in the setting of viral infections, malignancy, and autoimmune disease.51,52 FCG2B is the target of Xmab5871, a drug in phase 1 and 2 trials for autoimmune disease.28 IGFBP3 is a carrier for insulin-like growth factor 1 (IGF1).