TREM-2 expression is positively correlated with both disease progression and macrophage recruitment in PSC and PBC patients and in corresponding mouse models, suggesting that TREM2 overexpression is a mechanism that responds to cholestasis by repressing the proinflammatory activation of liver macrophages, a process that is amplified by UDCA. The gene discussed is TREM2; the disease is primary biliary cholangitis.