However, LSD1/KDM1 can also act as a transcriptional activator for instance through demethylation of lysine 9 in histone H3 in conjunction with androgen receptor-mediated transcription [44], through demethylation of lysine 9 in histone H3 in α-herpesvirus infections [49] or through demethylation of the E2F1 transcription factor which activates its apoptotic function [46]. This evidence concerns the gene E2F1 and Herpesviridae infectious disease.