PTEN and infection: In contrast to the expression pattern of miR-130b-3p (Figure 1a,b), we detected a lower expression level of PTEN in MG-infected DF-1 cells (Figure 5b) and chicken embryo lungs on days 5, 7, and 9 post-infection (equivalent to days 14, 16, and 18 of eggs hatching) (Figure 5a) compared with the corresponding control group.