CTSC and neoplasm: Tumor cells can also induce NET formation by secreting a variety of other stimulating factors, such as exosome, transforming growth factor-β (TGF-β), interleukin-1β (IL-1β), extracellular RNA (exRNA), mitochondrial DNA (mtDNA), high mobility group box-1 (HMGB1), cathepsin C (CTSC), tissue inhibitor of metalloproteinases-1 (TIMP-1), CXCL5 (59–69).