THBS1 and hepatocellular carcinoma: In one ASL and two HCC tumors, we discovered recurrent frameshift deletions in HSPG2 (Heparan Sulfate Proteoglycan 2) which encodes the perlecan protein, a key component of the vascular extracellular matrix, which modulates inhibition of angiogenesis by TSP1 (Thrombospondin 1)28.