Another group used lung cancer cell H460 membranes to bind two peptides, PD-L1 inhibitory peptide (TPP1) and MMP2 substrate peptide (PLGLLG), to coat superparamagnetic iron oxide nanoparticles through the homotypic effect of tumor cell membranes and the specific digestion of tumor-specific enzyme MMP2. Here, MMP2 is linked to lung cancer.