HDAC9 and non-small cell lung carcinoma: Among the targeting agents, studies have shown that the PPAR-γ agonist rosiglitazone facilitated the antiproliferative effects of gefitinib by upregulating PTEN expression in NSCLC A549 cells (166), while combination differentiation-based therapy involving PPAR-γ ligands and HDAC inhibitors enhanced the growth inhibition of lung adenocarcinoma cells (167).