To date, six PCPA-based LSD1 inhibitors, including TCP, ORY-1001 [43], GSK-2879552 [31,44], INCB059872 [32,33], IMG-7289, and ORY-2001, have reached the clinical trial stage, either alone or in combination with other therapies, for the treatment of cancers and neurodegenerative disorders [34,37,45]. This evidence concerns the gene KDM1A and cancer.