(a) Gene expression levels of anti-inflammatory marker genes (Mrc1, Arg1, Retnla, Chil3) and pro-inflammatory marker genes (Cd86, Il1b, Tnf, Cxcl1) measured by qPCR in BMDMs with or without Lgr4 depletion at basal conditions, or treated with Rspondin3, LPS alone or combination of both for 24h from three independent experiments with n=3 samples per group (mean ± sd); Statistical significance was determined by two-way ANOVA with Sidak’s multiple comparisons test using GraphPad Prism with individual P values (left to right) are: Mrc1 (ns P=0.9997, ****P<0.0001, ns P>0.9999, *P=0.0488), Arg1 (ns P=0.9708, ****P<0.0001, ns P=0.3532, ****P<0.0001), Retnla (ns P=0.7211, ****P<0.0001, ns P=0.9663, ****P<0.0001), Chil3 (ns P=0.6858, ****P<0.0001, ns P=0.6939, ***P=0.0001), Cd86 (ns P=0.3993, *P=0.0419, ****P<0.0001, ****P<0.0001), Il1b (ns P=0.8936, ns P=0.8526, ****P<0.0001, ****P<0.0001), Tnf (ns P>0.9999, ns P=0.3417, ****P<0.0001, ****P<0.0001), Cxcl1 (ns P=0.9976, ns P=0.9584, ****P<0.0001, ****P<0.0001). (b) mRNA levels of Lgr4 in sorted IM and AM measured by qPCR; n=3 samples per group (mean ± sd), two-sided unpaired t-test was determined using GraphPad Prism. **P=0.0012. (c) Levels of LGR4 in myeloid populations in mice lung evaluated by CyTOF (Data are representative of three independent experiments with n=5 mice per group). Graphs show the mean ± s.d, with each dot representing an individual mouse. Statistical significance was determined by ordinary one-way ANOVA with Dunnett’s multiple comparisons test using GraphPad Prism. ****P<0.0001. (d) Levels of LGR4 in IM in WT and Lgr4Mφ−/− mice with or without rRspondin3 i.v. under baseline conditions and post sublethal LPS challenge for 24h measured by CyTOF (Data are representative of three independent experiments with n=5 mice per group). Graphs show the mean ± s.d, with each dot representing an individual mouse. Statistical significance was determined by two-way ANOVA with Tukey’s multiple comparisons test using GraphPad Prism with individual P values (left to right) are: ****P<0.0001, ****P<0.0001, ****P<0.0001, ****P<0.0001.