Indeed, it has been reported that LSD1 is overexpressed in various human cancers: including breast and colon cancers, and neuroblastoma.(12–14) In such cancer cells, knockdown or pharmacological inhibition of LSD1 is reported to suppress tumor cell growth.(15) Therefore, the inhibition of LSD1 activity would be not only a potential therapeutic strategy for cancers but also a chemical method to research biological significance of LSD1 in physiological and pathological events. This evidence concerns the gene KDM1A and cancer.