IGFBP6 and Sepsis: Notably, TLR signaling pathway analysis revealed that TLR2 and/or TLR4 deficiency substantially attenuated IGFBP6 expression in PLF, pulmonary tissue, macrophages, and epithelial cells during sepsis (Supplemental Figure 5, A–E), establishing TLR2/4-mediated regulation of IGFBP6 production.