CST3 and infection: Additionally, MSCs create an anti-inflammatory environment, protecting against further development of infection and minimizing the risk of progression of cellular damage by secreting antimicrobial peptides (AMPs), such as cystatin C (CST3), elafin, hepcidin, cathelicidin-4 (CATHL4, indolicidin), lipocalin-2 (LCN2) or IDR-1, disrupting the integrity of bacterial cell membranes17–21.