ERBB2 and neoplasm: Liposomal metformin which inhibits mitochondrial respiration, relieved tumor hypoxia to enhance PDT (Figure 12E).[151] Liposomal gold (Au) nanoclusters inhibited thioredoxin reductase (TrxR) to enhance tumor PDT (Figure 12F).[152] After the liposome was internalized specifically by tumor cells into the acidic lysosome via antibody HER2, malachite green carbinol base (MG), a pH responder anchored on the liposome membrane, was converted to MG carbocation (MG+), leading to liposome collapse and the payload release of Au nanoclusters and Ce6.