Description_x000D_ Biochem/physiol Actions_x000D_ ST1926 is an atypical retinoid that is able to overcome resistance to ATRA. ST1926 appears to induce apoptosis by production of DNA double-strand breaks (DSB) and chromosomal lesions during the S phase of the cell cycle._x000D_ ST1926 is considered to be more apoptotic than CD437. It is much effective in mobilizing calcium than CD437. ST1926 repress toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signal pathway to disable the actions of nuclear factor-κB (NF-κB). It has the ability to repress inflammation response and ROS synthesis in lung epithelial cells in vitro.