NMS-873 is a potent and selective allosteric inhibitor of the heat shock protein 70 (Hsp70) family. It is primarily used in research settings to study the role of Hsp70 in cellular processes such as protein folding, degradation, and stress response. By inhibiting Hsp70 ATPase activity, NMS-873 disrupts chaperone function, leading to the accumulation of misfolded proteins and induction of proteotoxic stress in cells. This compound has shown promise in preclinical cancer research, particularly in models where cancer cells rely heavily on Hsp70 for survival, such as in certain solid tumors and hematological malignancies. It can sensitize tumor cells to other stress-inducing therapies, including chemotherapy and heat shock protein 90 (Hsp90) inhibitors, making it a candidate for combination treatment strategies. Due to its ability to trigger apoptosis in cancer cells with minimal effect on normal cells under some conditions, NMS-873 serves as a valuable tool for validating Hsp70 as a therapeutic target. However, it remains a research compound and is not used clinically.