HO-1-expressing macrophages were shown to possess a tendency towards an M2 phenotype polarization that contributes to upregulation of anti-inflammatory cytokine (IL-10) expression, suppression of pro-inflammatory cytokine (TNFα) secretion and expression of reparative genes that are beneficial to tissue recovery following AKI [71,72]. The gene discussed is HMOX1; the disease is acute kidney injury.