INCB059872, also known as INCB59872, is a potent, selective, and orally active lysine-specific demethylase 1 inhibitor. INCB059872 binds to and inhibits LSD1, a demethylase that suppresses the expression of target genes by converting the di- and mono-methylated forms of lysine at position 4 of histone H3 (H3K4) to mono- and unmethylated H3K4, respectively, through amine oxidation. LSD1 inhibition enhances H3K4 methylation and increases the expression of tumor-suppressor genes. In addition, LSD1 demethylates mono- or di-methylated H3K9 which increases gene expression of tumor promoting genes; inhibition of LSD1 promotes H3K9 methylation and decreases transcription of these genes.