HDAC9 and pulmonary fibrosis: Thus, although pan-HDAC inhibitors were shown to reduce lung fibrosis through the induction of significant myofibroblast apoptosis in bleomycin-treated mice, they appeared to reverse the aberrant hyperplastic (cytokine-releasing) phenotype of fibrotic AECII as well as to spare injured pro-apoptotic AECII from further apoptosis [164,168], thereby targeting two different AECII states in the fibrotic lung to promote proSP-C+ AECII re-differentiation, proSP-C+ AECII survival and proper re-epithelialization of the damaged alveolar epithelium as a therapeutic strategy.