KIRA9

**KIRA9** is a potent small molecule inhibitor of IRE1α (Inositol-requiring enzyme 1 alpha), a key endoplasmic reticulum (ER) stress sensor involved in the unfolded protein response (UPR). It fully engages the ATP-binding site of IRE1α, potently inhibiting its RNase activity with reported IC50 values of 4.8 μM in INS-1 cells and 39 nM for RNase inhibition, thereby blocking ER-localized mRNA decay (RIDD) and ER stress-induced apoptosis. Primarily utilized as a research tool, KIRA9 has been characterized in preclinical studies for its ability to modulate IRE1α signaling, with no evidence of clinical development or approved indications.[1][2][3][5]