TREM2 and acute lung injury: Further investigations have illuminated that in the context of sepsis-induced acute lung injury in murine models, TRIM21 (tripartite motif-containing protein 21) attenuates the expression of IRF1 (interferon regulatory factor 1) through the mechanism of ubiquitination, thereby reinstating TREM2 expression and ameliorating sepsis-induced acute lung injury (SI-ALI) (60).