– LSD1 belongs to the flavin monoamine oxidase family. It contains 1 SWIRM domain and is a component of an RCOR/GFI/LSD1/HDAC complex. LSD1 interacts directly with GFI1 and GFI1B. LSD1 specifically removes histone H3K4me2 to H3K4me1 or H3K4me0 through a FAD-dependent oxidative reaction. When forming a complex with an androgen receptor (and possibly other nuclear hormone receptors), LSD1 changes its substrates to H3K9me2. Thus LSD1 is considered to act as a coactivator or a corepressor. It may play a role in the repression of neuronal genes. Alone, LSD1 is unable to demethylate H3 ‘Lys-4’ on nucleosomes and requires the presence of RCOR1/CoREST to achieve such activity.