Provided herein are protein biomarkers for NETosis related diseases, including proteases. Also provided are substrate sequences of such proteases and uses thereof. Neutrophils are the most abundant leukocytes in plasma. They are the first cells recruited to injury sites in response to pathogen invasion, and they act in the first line of innate immune defense. Neutrophils have traditionally been considered effector cells for inflammatory response and acute immunity, functioning through intracellular phagocytosis, and using lytic proteases, reactive oxygen species (ROS) and microbicidal proteins for attack of infective agents.