FCN2 and autoimmune thrombocytopenic purpura: MBL2, FCN2, and CFP are predominantly produced in the liver.[37] The liver plays a role in platelet production by secretion of thrombopoietin (TPO).[38] Our study identified a potential mechanism for the pathogenesis of ITP, indicating that abnormal activation of the liver‐associated lectin complement pathway may play a role in platelet destruction and immune responses facilitated by exosomes.