MMP9 and Sepsis: A recent study using single-cell and gene expression data of sepsis patients revealed that neutrophils were the second most prevalent cell type, and could be categorized into five distinct subsets: colony stimulating factor 3 receptor (CSF3R) neutrophils, matrix metalloproteinase-9 (MMP9) neutrophils, LYZ neutrophils, S100A9 neutrophils, and cystatin 3 (CST3) neutrophils.