Fetal liver chimeric (FLC) mice reveal that CXCR3 expression in the hematopoietic system promotes DMBA/TPA induced epidermal proliferation. (A) The indicated mice were generated with fetal liver transplantation of irradiated recipients and treated with short course DMBA/TPA (**p<0.01, n=3 for WT→WT, n=3 for WT→RAG2−/−, n=4 for WT→ CXCR3−/− and n=4 for CXCR3−/−→RAG2−/−, combined from 2 different experiments). BrdU incorporation was then determined and all mice (representative section in B of WT→CXCR3−/−) displayed WT levels of proliferation, except the CXCR3−/−→RAG2−/− (representative section in C).