In the PM2.5-induced acute lung injury model, PM2.5 can stimulate the generation of reactive oxygen species, which activate the phosphorylation site Thr845 of ASK1 and thus activate the p38 and JNK signalling pathways and cause apoptosis of airway epithelial cells, eventually leading to acute lung injury (Ni et al., 2015). Here, MAP3K5 is linked to injury.