HDAC4 and cancer: However, this was inconsistent with the previous reports, in which Ablating HDAC4 signaling induced Hif1α protein acetylation, reduced Hif1α protein level in cancer cell lines (Geng et al. 2011; Isaacs et al. 2013; Ellis et al. 2009), and inhibited endothelial tumor angiogenesis (Geng et al. 2011; Cadot et al. 2009; Liu et al. 2009; Mottet et al. 2009).