Histone deacetylase inhibition, histone demethylase inhibition, and hypomethylating agents are an active area of development for many cancers. MCC harbors numerous epigenetic changes as detailed in the text. The sTAg activates the lysine-specific histone demethylase (LSD1) and is required for tumorigenesis. Here, KDM1A is linked to Merkel cell skin cancer.