A recent study on adult cirrhotic livers described a population of scar-associated macrophages in cirrhosis [46] that appear most similar to cholestatic LAM and express higher levels of TREM2, CD9, LGALS3, and SPP1. Future studies will more clearly define the similarities and differences in subset-specific macrophage function by patient age, stage of cholestatic liver disease, and etiology of cirrhosis. The gene discussed is TREM2; the disease is Cholestatic liver disease.