The aim of the present review is to survey the accumulated knowledge on the 
extracellular matrix (ECM) of tumors referring to its putative utility as 
therapeutic target. Following the traditional observation on the extensive 
morphological alteration in the tumor-affected tissue, the well-documented 
aberrant cellular regulation indicated that ECM components have an active role 
in tumor progression. However, due to the diverse functions and variable 
expression of proteoglycans, matrix proteins, and integrins, it is rather 
difficult to identify a comprehensive therapeutic target among ECM components. 
At present, the elevated level of heparanase and the prominent expression of 
αvβ5 integrin are considered as promising therapeutic targets. The inhibition of 
glycosaminoglycan offers another promising approach in the treatment of those 
tumors which are stimulated by proteoglycans. It can be ascertained that a 
selective ECM inhibitor would be a great asset to control metastasis driven by 
ECM-mediated signaling.