Further mechanistic insights in breast cancer cells, reported in a study by Roucourt et al. [96], demonstrated that, through its HS-degrading activity, heparanase favors syndecan-1 clustering and formation of a complex containing syndecan-1, the scaffolding protein syntenin, and α-1,3-mannosyltransferase (ALG-2)-interacting protein X (ALIX), a component of the endosomal-sorting complex required for transport (ESCRT) which drives exosome production [97]. The gene discussed is HPSE; the disease is breast cancer.