LL-37 is commonly secreted by epithelial cells and phagocytic macrophages to fight Gram-positive and Gram-negative bacterial infections, but it is also expressed by MSCs.82, 83, 84 LL-37 production is a systemic control against bacteria and sepsis, with MSCs secreting the peptide in response to Escherichia coli and other microbes.85, 86, 87 This discovery suggests that MSCs are a potential therapeutic agent for acute and systemic infections. Here, CAMP is linked to gram-negative bacterial infections.