ZnPc-O3-JQ1 is a light-activated BRD4 degrader. Under light exposure, ZnPc-O3-JQ1 generates reactive oxygen species (ROS), leading to the degradation of BRD4. This degradation results in the downregulation of HIF-1α, effectively countering the tumor hypoxia-induced resistance to photodynamic therapy (PDT). ZnPc-O3-JQ1 exhibits both Type I and Type II PDT mechanisms. The structure of ZnPc-O3-JQ1 includes three components: a BRD4 ligand, a linker, and a photosensitizer.