SERPING1 and hereditary angioedema: A predominance in females is associated with the estrogen hormone, a hallmark of HAE with normal C1-INH.5, 7Estrogen has a regulatory role in the synthesis of FXII protein, as well as of several genes and proteins of the coagulation cascade and of the kallikrein-kinin system, increasing synthesis of bradykinin, kallikrein, vascular permeability and consequently causing edema.9This association is important in worsening the attacks in women, ranging from childhood, puberty, menses, pregnancy and menopause.1