Similar to prior reports in both Ewing sarcoma and DSRCT (32, 60), cell viability was affected by both of the noncompetitive inhibitors, SP-2509 and seclidemstat, but not OG-L002, indicating that for all of the tumor types tested, inhibition of the catalytic function of LSD1 is not a sufficient antitumor strategy. The gene discussed is KDM1A; the disease is Ewing sarcoma.