Furthermore, a study of systemic delivery (by intravenous injection) of enhancer of zeste homolog 2 (EZH2) and phosphoinositide 3′-hydroxykinase p110-α-subunit (p110-α) siRNA/atelocollagen to bone-metastatic tumors revealed that atelocollagen can efficiently deliver nucleic acids to tumors and causes an inhibition of metastatic tumor growth. This evidence concerns the gene EZH2 and metastatic neoplasm.