In myeloma patients, heparanase enzymatic activity was elevated in the bone-marrow plasma of 86% of patients examined,87 and gene array analysis showed elevated heparanase expression in 92% of myeloma patients.57 Heparanase up-regulation in myeloma patients was associated with elevated microvessel density and syndecan-1 expression.87 While heparanase is proangiogenic in myeloma, which is a common feature shared with solid tumors, heparanase regulation of syndecan-1 shedding has emerged as highly relevant to multiple myeloma progression. Here, HPSE is linked to AL amyloidosis.