SMAD2 and Hepatic fibrosis: sTREM‐1 has synergistic effect with CCl4 on liver fibrosis via Robo2‐Smad2/3 and PI3K/Akt pathway, knocking down Robo2 or inhibiting Smad2/3 or PI3K/Akt significantly blocked the sTREM‐1‐induced HSC activation and liver fibrosis.