Attenuated androgens and tranexamic acid were used for on‐demand treatment of attacks in 20% of patients with HAE Type 1/2. 17 patients with HAE Type 1/2, 8 patients with nC1‐INH‐HAE with F12 mutation, and 16 patients with nC1‐INH‐HAE with unknown mutation treated acute attacks with C1‐INH and/or icatibant. This evidence concerns the gene COL18A1 and hereditary angioedema.