The sialic acid binding Ig-like lectin F (SiglecF)+ C-X3-C motif chemokine receptor 1 (CX3CR1)+ macrophages were also identified in pulmonary fibrosis mouse model, which were adjacent to fibroblasts and promoted fibrosis by releasing PDGFs to drive the proliferation and activation of fibroblasts77. The gene discussed is CX3CR1; the disease is pulmonary fibrosis.