First, in MERS‐CoV related studies, Ahmed et al found that spike glycoprotein MERS‐CoV suppressed macrophage responses via DPP‐4‐mediated induction of interleukin‐1 receptor‐associated kinase (IRAK)‐M and peroxisome proliferators‐activated receptor γ (PPARγ) at the early stage of infection.19 Here, DPP4 is linked to infection.