SIRT6 and idiopathic pulmonary fibrosis: Interestingly, in vitro models using cultured primary human bronchial epithelial cells (HBEC) by Minigawa et al. [42] showed that transforming growth factor β (TGF-β), a profibrotic mediator, induces cellular senescence and increases expression of Sirtuin 6 (SIRT6), a class III histone deacetylase (HDAC) expressed in epithelial cells in an IPF lung.