Moreover, this protein in its mutated form (L68Q) is associated with the occurrence of hereditary cystatin C amyloid angiopathy (HCCAA), also known as Icelandic-type amyloidosis or type VI amyloidosis (for review see: [13,14]), where HCC molecules build up fibrillary deposits in the blood vessels causing hemorrhages, typically gradually leading to the death of relatively young patients (20–30 years old), although the case of an elderly patient has also been recorded [14,15,16]. The gene discussed is CST3; the disease is hepatocellular carcinoma.