MCL1 and Arthritis: employed PEI‐based NPs fortified with photosensitizers for co‐delivering the chemotherapeutic drug tirapazamine and MCL‐1 siRNA, and this strategy effectively silenced MCL‐1 in macrophages.[197] The combined effects of MCL‐1 siRNA‐mediated RNA interference, photodynamic therapy and tirapazamine hypoxia‐activated chemotherapy led to a reduction in ankle joint swelling and erythema, markedly alleviating arthritis inflammation in AIA rats, as demonstrated by the H&E staining results.