Similarly, enhancing this targeted nanobubble concept with combined photodynamic therapy (PDT), Cai et al. (2023) conjugated HER2-specific affibodies to pre-formed nanobubbles loaded with near-infrared photothermal probe IR783 and photosensitizer 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) through a biotin–streptavidin system to form nanobubble-IR783-HPPH-affibody (NIHA) complexes, enabling laser-activated PDT for HER2-positive breast cancer, with significant increases in ROS production and tumor cell death in vitro and in vivo [67]. Here, ERBB2 is linked to breast carcinoma.