TEK and neoplasm: However, due to its size (340 kDa), complex quaternary structure (homo-octamer), and proteinaceous nature, any pharmacological application of PTX3 protein appears unrealistic unless functional “shuttles” can be identified for this “cargo.” One possibility for a direct therapeutic exploitation of the PTX3 protein has been shown by using “tumor targeting” Tie2+ monocytes (TEMs) (111) derived from the bone marrow of TgN(Tie2-hPTX3) mice (106).