True or False: Only the Classical complement pathway can be activated by any antigen or microbe.

The statement is false. The Classical complement pathway is indeed one of the pathways that can activate the complement system, but it is not the only pathway that can be initiated by antigens or microbes.

In addition to the Classical pathway, there are two other major pathways for complement activation: the Lectin pathway and the Alternative pathway. The Lectin pathway is activated by the binding of specific lectins to carbohydrates on the surface of pathogens, while the Alternative pathway can be spontaneously activated on pathogen surfaces without the need for antibodies. Both of these pathways can also respond to a wide variety of antigens and microbes.

Therefore, saying that only the Classical complement pathway can be activated by any antigen or microbe is inaccurate. The other pathways have unique mechanisms of activation and also play important roles in the immune response.