Serping1, also known as the C1 inhibitor (C1INH) encoding gene, plays a crucial role in the body. C1INH is a protease inhibitor that is the major control of the kallikrein-kinin system and also inhibits the C1r/C1s in the C1 complex of the classical complement pathway, preventing its spontaneous activation [1,3,4]. It is essential for maintaining the balance of the coagulation, complement, contact systems, and fibrinolysis [2].

Mutations in Serping1 are responsible for hereditary angioedema (C1-INH-HAE), an autosomal dominant disorder. Over 700 mutation variants have been described, with different phenotypes associated with the variants. For example, some dysfunctional serpin variants fail to associate with proteases and present a residual 105-kDa species after incubation with target protease. Also, in conditions with low antigenic C1Inh, some patients present an intermediate C1-INH-HAE phenotype [1]. In addition, Serping1 mRNA is overexpressed in monocytes from HIV-1 + patients, and its expression levels correlate with viral load and CD4+ T-cell count, indicating its role in the innate immune response to HIV-1 infection [3].

In conclusion, Serping1 is vital for regulating key physiological systems such as the kallikrein-kinin and complement systems. Its mutations are strongly linked to hereditary angioedema, and it also plays a role in the immune response to HIV-1. Understanding Serping1 through research, potentially including gene knockout models in the future, could further clarify its functions and provide insights for treating related diseases.