Next, we measured the circ_0001239 expression and found that the circ_0001239 expression was upregulated in the pulmonary tissue of neonatal mice with Spn-induced pneumonia but was downregulated in the pulmonary tissue with low expression of METTL3 (P < 0.01, Fig. 2C). This evidence concerns the gene METTL3 and susceptibility to pneumonia measurement.