The SBR resulting from afterglow images also increased linearly with tumor size, suggesting the potential of F12+-ANP-Gal for (a) accurate detection of early-stage liver tumors and (b) noninvasive monitoring of HepG2 tumor growth in living mice through afterglow imaging of H2S. Moreover, the enhanced penetration depth of NIR afterglow luminescence could allow F12+-ANP-Gal to sensitively detect orthotopic liver tumors, affording a large SBR (124.5 ± 12.5) to precisely position liver tumor foci in mice (Fig. 5). The gene discussed is NPPA; the disease is neoplasm.