Ezatiostat hydrochloride is primarily used in the field of oncology, particularly in the treatment of myelodysplastic syndromes (MDS). It functions as a glutathione analog prodrug, helping to restore glutathione levels in cells, which is crucial for maintaining cellular redox balance. This action supports the reduction of oxidative stress and promotes normal cellular function. In clinical settings, it has been explored for its potential to improve hematologic parameters in patients with MDS, offering a therapeutic option for those who may not respond well to other treatments. Additionally, its role in modulating immune responses and enhancing the efficacy of other anticancer therapies is under investigation, making it a promising candidate for combination therapies in cancer treatment.