Notably, the use of caspase inhibitors Z-DEVD-FMK and Z-LEHD-FMK, which specifically inhibit caspase-3 and caspase-9, respectively, can rescue cells from apoptosis induced by FIR treatment.<h4>Conclusion</h4>This study systematically elucidated that FIR exerts anti-tumor effects through multiple mechanisms, including inducing MM cell apoptosis, exacerbating hypoxic stress, and causing cell cycle arrest. The gene discussed is CASP9; the disease is neoplasm.