Application of the HDAC5 inhibitor LMK-235 reduced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in a dose-dependent manner, demonstrating that the HDAC5-ERK1/2 axis plays an important role in maintaining the stemness of lung cancer stem cells (93). The gene discussed is MAPK3; the disease is lung carcinoma.