In Nucleic Acids Research this week, researchers in Belgium and France report that LSD1 and CTIP2 work together to promote HIV-1 transcriptional silencing. In previous studies, the team showed that CTIP2 forces heterochromatin formation and HIV-1 gene silencing. In this study, the team shows that LSD1 represses HIV-1 transcription and viral expression in cooperation with CTIP2.