IgG molecules of the IgG1, IgG2, and IgG4 subclasses exhibit exceptionally long half-lives due to FcRn-mediated recycling. Half-lives of up to 4 weeks have been described for therapeutic antibodies. Learn more about Fc-fused protein Amplification: https://half-life-extension.creative-biolabs.com/fc-fusion-protein-development.htm