Substrate specificity and regulation of gene expression by LSD1. a The binding of LSD1 to the CoREST, CtBP or NuRD complex allows the demethylation of H3K4me1/2 and leads to the transcriptional repression of target gene. b LSD1 catalyzes the demethylation of the repressive mark H3K9me2 when it interacts with the AR or ERα, thus activating the target gene expression. c LSD1n, a neuronal-specific isoform, demethylates the repressive mark H4K20me2, by interacting with CREB (cAMP-response element-binding protein) and MEF2 (myocyte enhancer factor 2)