ACVRL1 and infection: Moreover, we used intravital microscopy (IVM) to visualize and quantify the bacterial capture within the liver and to understand the mechanism underlying the increased susceptibility to infection and found that Alk1/Smad4-deficient mice showed a significant reduction in the capture of circulating L. monocytogenes by KCs (Figure 10, C and D, Supplemental Figure 8B, and Supplemental Videos 1–3), despite having a similar number of KCs compared with their controls (Supplemental Figure 7, E and F).