We initially selected leiomyosarcoma SK-LMS-1 cells, deleted for HDAC4 using CRISPR/Cas9 and re-expressing a 4-hydroxytamoxifen (4OHT)-inducible PAM mutant version of HDAC4 (HDAC4−/−/HDAC4PAM-ER) as a model of inducible senescence (9). This evidence concerns the gene HDAC4 and leiomyosarcoma.