APY29 is primarily used in biochemical and pharmacological research as a potent and selective inhibitor of the IRE1α-XBP1 pathway. This pathway is a critical component of the unfolded protein response (UPR) in cells, which is activated under conditions of endoplasmic reticulum (ER) stress. By inhibiting IRE1α, APY29 helps researchers study the role of this pathway in various cellular processes, including apoptosis, inflammation, and autophagy. It is particularly valuable in understanding the mechanisms underlying diseases such as cancer, neurodegenerative disorders, and diabetes, where ER stress and the UPR play significant roles. Additionally, APY29 is utilized in drug discovery efforts to identify potential therapeutic targets for conditions linked to dysregulated ER stress responses.