AIM: To investigate the regulation of lysine specific demethylase 1( LSD1) inhibition on differentiation of human induced pluripotent stem cells( hiPSCs) into definitive endoderm( DE). METHODS: LSD1 expression was inhibited by LSD1 inhibitor or shRNA. The morphological changes of hiPSCs were traced by microscopy,and LSD1 activity was measured by corresponding kit. The cell viability was detected by CCK-8 assay. The expression of hiPSCs pluripotency genes and germ layer specific genes was analyzed by qPCR,an...