OMI (Uniprot ID O43464) is a pro-apoptotic protease localized to the mitochondria which was hypothesized to activate senescense following X-ray irradiation via cleavage of specific ligands. To elucidate cellular processes affected by OMI after irradiation, human lung cancer cell line was subjected to the following treatments: WT + X-ray irradiation WT - X-ray irradiation WT + OMI-inhibitor + X-ray irradiation WT + OMI-inhibitor - X-ray irradiation OMI-siRNA + X-ray irradiation OMI-siRNA - X-ray irradiation siRNA-empty vector (control) + X-ray irradiation siRNA-empty vector (control) - X-ray irradiation