In COPD, CS influences genes such as PARP1, PDE4A, PDE4B, PDE4C, PDE4D, PTGDR2 (p = 4.61e‐03, TTD), HMOX1, and MMP1 (p = 3.65e‐02, OMIM). The gene discussed is PDE4C; the disease is chronic obstructive pulmonary disease.