Decreased mRNA expression or protein levels for TGFβ1, TGFBR1 [41], SMAD3 [42], SMAD6 [43], and SMAD7 [41,43] have been reported in more advanced stages of COPD or fibroblasts from COPD patients. The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.