SERPING1 and respiratory distress syndrome in premature infants: C1INH (https://www.uniprot.org/uniprot/P05155), also known as Serpin Peptidase Inhibitor Clade G Member 1 (SERPING1), has gained increasing attention as a regulator of several systems such as the complement system, plasma kallikrein of the contact system (which plays a central role in RDS etiopathology), the coagulation system (factor XIIa, XIa, and thrombin), and the fibrinolytic system through the inhibition of plasmin, and tissue-type plasminogen activator (10).