C4A and hereditary angioedema: Interestingly, previous studies identified that in a cohort of patient’s carriers of Hereditary Angioedema (HAE), presenting both type I or II phenotypes of the disease, a fall in the levels of MASP1-C1INH complexes, which was correlated with several aspects of the disease, including, C4 consumption and the number of attacks through the year of blood samples drawing (75).