MMP2 and cancer: The PMB, designated as compound 1, integrates a distyryl boron dipyrromethene (DSBDP)-based photosensitizer with a Black Hole Quencher 3 (BHQ-3) moiety, connected via two peptide segments that serve as substrates for matrix metalloproteinase-2 (MMP-2) and cathepsin B, enzymes commonly overexpressed in cancer cells.