They also used double-stranded DNA (dsDNA) as the rigid support for Au nanocage and MMP-2 cleavable peptide that facilitates the destruction of Au nanocages by MMP-2 enzyme that are overexpressed in the tumor microenvironment, resulting in multifunctional and tumor-specific gene therapy, CTX, and PTT [177]. The gene discussed is MMP2; the disease is neoplasm.