Given that the expression of diverse profibrotic cytokines is the hallmark of fibrosis and the most prominent factor known to promote the progression of pulmonary fibrosis is TGF-β1 [33], we analyzed the expression of TGF-β1 in the lung tissues of MERS-CoV-infected mice and compared it with that in non-treated control hDPP4-Tg mice. The gene discussed is TGFB1; the disease is pulmonary fibrosis.