PU-H71 is primarily used in cancer research and treatment due to its ability to inhibit the heat shock protein 90 (HSP90). This protein plays a crucial role in stabilizing and activating various client proteins involved in cancer cell growth and survival. By targeting HSP90, PU-H71 disrupts the function of these client proteins, leading to the degradation of oncogenic proteins and ultimately inhibiting tumor growth. It has shown promise in preclinical studies for treating various cancers, including breast cancer, leukemia, and lymphoma. Additionally, PU-H71 is being investigated for its potential to enhance the efficacy of other cancer therapies when used in combination. Its selective targeting of tumor cells while sparing normal cells makes it a promising candidate for developing safer and more effective cancer treatments.