THBS1 and Familial prostate cancer: Expression array showed that in prostate cancer cells VPA induces the up-regulation of TSP1 (Thrombospondin-1), multiple TIMP (Tissue inhibitor of metalloproteinase) isoforms and TGFβ (Transforming growth factor β), while expression of IGF1 (Insulin like growth factor 1) and VEGF is decreased [115].