PSMs induce the necroptosis of neutrophils through the activation of mixed-spectrum kinase-like protein (MLKL) phosphorylation and increased release of lactate dehydrogenase, which mediates TNF-α secretion via formyl peptide receptor 2 (FPR2) and leads to the exacerbation of pneumonia [68]. This evidence concerns the gene FPR2 and susceptibility to pneumonia measurement.