TMPRSS2 expression was found to be up-regulated in the lungs of smokers and COPD patients when compared to control tissues (Saheb Sharif-Askari et al, 2020; Fließer et al, 2021; Watson et al, 2021; Brake et al, 2022). The gene discussed is TMPRSS2; the disease is chronic obstructive pulmonary disease.