mRNA and protein expressions of apoptosis-related factors Bax and Bcl-2 were measured by qRT-PCR and Western blot in order to investigate how miR-143-3p mediated TLR4/MyD88/NF-κB signaling pathway to work on the apoptosis of alveolar epithelial cells of mice with mycoplasmal pneumonia (Figure 4). This evidence concerns the gene MYD88 and Mycoplasma pneumoniae pneumonia.