SAA3P and bacterial infectious disease: Consistent with these findings, previous in vivo studies demonstrated the protective role of SAA3 in bacterial infections via macrophage-derived IL-1β production.60,61 Therefore, it is possible that early SAA3 secretion by trained macrophages may be important to control the acute phase of bacterial infections.62,63 Although SAA3 is not present in humans, its identification as a trained-immunity-related protein highlights the potential clinical relevance of SAA family proteins as biomarkers in immune-related diseases.64–66