The myeloperoxidase (MPO), a heme‐containing enzyme, converts hydrogen peroxide (H2O2) and Cl‐ to H2O to form hypochlorous acid (HOCl), a powerful oxidant of the reactive oxygen species (ROS) family.[241] MPO/HOCl pathway was activated by hSOD1G93A mutation in SOD1G93A ALS NSC‐34 motor neuron models. Here, MPO is linked to amyotrophic lateral sclerosis.