HDAC5 protein in skeletal muscle of COPD patients (0.44 ± 0.26) was also significantly lower than that of SM (1.29 ± 0.39, p = 0.0001) and NS (0.98 ± 0.43, p = 0.020; Fig. 1b). The gene discussed is HDAC5; the disease is chronic obstructive pulmonary disease.