NR1I2 and infection: In addition, M. hyopneumoniae-infected normal PAM 3D4/21 cells significantly increased gene and protein expression levels of CYP3A29, while the silencing of PXR decreased the expression of CYP3A29, and the overexpression of PXR increased the expression of CYP3A29. Our study is consistent with previous studies, and based on the pathogen infection pattern, our study validated that PXR could upregulate the expression of CYP3A29 during M. hyopneumoniae infection in PAM cells.