TLR4 and Hepatic fibrosis: Chimeric mice with TLR4 wild-type HSCs and TLR4 mutant Kupffer cells are more sensitive to chemically-induced liver fibrosis compared with TLR4 mutant C3H/HeJ mice and those mice with TLR4 mutant HSCs, but wild-type TLR4 Kupffer cells, indicating the crucial role of TLR4 expression in HSCs12.