Passive and active targeting can cause accumulation of multifunctionalized GNPs in tumor tissues. Several anticancer drugs, such as paclitaxel, doxorubicin and platinum-based drugs have been covalently or noncovalently conjugated to GNPs to form multifunctionalized GNPs for cancer therapy. After internalized by tumor cells, multifunctionalized GNPs can release the entrapped therapeutic drugs in a controlled manner.