+**F2b**
+F2b is a crucial fragment of a [Protein](/wiki/Protein) involved in the [Complement System](/wiki/Complement_System). It plays an essential role in the alternative pathway, aiding the body's rapid immune response. This active component is vital for host defense against pathogens.
+## See also
+- [Immunity](/wiki/Immunity)
+- [Pathogen](/wiki/Pathogen)
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