PROBLEM TO BE SOLVED: To provide a potentiator of effects of a therapeutic agent for cancer and an anticancer agent, and to provide an expression suppressant of HCP-1 (Heme Carrier Protein 1).SOLUTION: The potentiator of effects of a therapeutic agent for cancer and an anticancer agent, or the expression suppressant of HCP-1 contains a substance inhibiting expression of a gene encoding a vascular endothelial growth factor or a substance inhibiting a function of a vascular endothelial growth factor.COPYRIGHT: (C)2012,JPO&INPIT【課題】癌治療剤、抗癌剤の効果増強剤及びHCP-1の発現抑制剤の提供。【解決手段】血管内皮細胞増殖因子をコードする遺伝子の発現を阻害する物質又は血管内皮細胞増殖因子の機能を阻害する物質を含む、癌治療剤、抗癌剤の効果増強剤又はHCP-1の発現抑制剤。【選択図】なし