As shown in Fig. 6b-c, InCasorND4 produced obvious fluorescence signals in both HepG2 and MDA-MB-231 tumor tissue, while the probe targeting the mutant ND4 gene (InCasorND4-2-MT) only produced signals in MDA-MB-231 tumors, demonstrating the ability of InCasor for in vivo imaging of an mtDNA mutation. The gene discussed is MT-ND4; the disease is neoplasm.