This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Anatomy
Thrombospondin is: 
Select and explain. 
A. Coagulation protein, B. Coagulation promoting protein, C. Contractile protein, D. Angiogenesis inhibiting protein
D: Angiogenesis inhibiting protein
Answer: D: Angiogenesis inhibiting protein 
Explanation: Thrombospondin is a family of large multi functional proteins some of which similar to SPARC inhibit angiogenesis. The production of thrombospondin-1 has been shown to be inversly related to the ability of a cell line to produce a tumour and vessels in vivo loss of thrombispondin -1 production allowed nin tumorogenic cells to become tumourogenic.(ref Robbins 9/e p306)