MKC-3946 is a potent inhibitor of the IRE1α pathway, which plays a key role in the unfolded protein response (UPR) associated with endoplasmic reticulum (ER) stress. This compound is primarily used in research settings to study cellular stress responses, particularly in cancer and inflammatory diseases. By selectively blocking IRE1α’s RNase activity, MKC-3946 helps modulate the degradation of XBP1 mRNA, a critical signaling component in plasma cell differentiation and survival. It has shown potential in preclinical models for enhancing the efficacy of other anticancer agents, especially in multiple myeloma and solid tumors where ER stress pathways are hyperactive. Its application also extends to studying neurodegenerative conditions and metabolic disorders linked to chronic ER stress, making it a valuable tool in probing disease mechanisms and therapeutic strategies.