Based on observational studies and case reports, however, on demand (e.g., icatibant and plasma-derived C1 inhibitor [pdC1-INH] and long-term prophylaxis treatments (e.g., lanadelumab, pdC1-INH, and berotralstat) for HAE-C1-INH may be effective in some patients with HAE nC1-INH or AE-UNK [1, 11, 12]. This evidence concerns the gene COL18A1 and hereditary angioedema.