Figure 4. Activation of hepatic stellate cells (HSCs).(A) Hypothesis of the arginase in the TAM inducing the activation of HSCs to differentiate into cancer-associated fibroblasts (CAFs), which further aggravating the immune evasion. (B) Proline production by RAW 264.7 (Inactivated), M1 macrophage, M2 macrophage, and M2 macrophage incubated with BEC. (C) Measurement of proline secreted by M2 macrophage incubated with BEC for incremental time. (D) LX-2 cells, a HSCs cell line were incubated with DMEM (Control), DMEM from M2 macrophage, DMEM with 10 μg/mL proline, DMEM with 10 μg/mL aspartate, and 10 μg/mL cysteine, respectively. Then, the FAP in LX-2, a marker of CAFs, were imaged using 10 μM/mL Cy-FAP. (E) Fluorescence intensity output of Figure 4D. The data are expressed as mean ± SD. n = 3. Scale bar= 25 µm.