We found that ∼11% of intracellular L. monocytogenes cells remained trapped in LAMP-1-positive vacuoles 2 h post-infection, which increased to 20% in stimulated HBCs (Fig. 3A and B), consistent with the notion that HBCs may successfully kill a small proportion of phagosomal L. monocytogenes. This evidence concerns the gene LAMP1 and infection.