The nanostructure swelled in a weakly acidic tumor niche due to the protonation of the functional 3-diethylaminopropyl isothiocyanate (DEAP), and released the loaded NLG919 due to the cleavage of the peptide substrate by matrix metalloproteinase-2 (MMP-2) (Cheng et al., 2018). The gene discussed is MMP2; the disease is neoplasm.