The requirement for SIRT7 inSIRT1-dependent EMT promotion might also be relevant for understanding theobservation that in contrast to the EMT- and metastasis- promoting effects of SIRT7reported in prostate cancer cells23, other work reported that inbreast cancer cells, SIRT7 suppresses EMT and tumor metastasis via deacetylation ofthe Smad4 transcription factor28. Here, SIRT7 is linked to cancer.