Motor neurons (MN) are specialized neurons originating from the spinal cord, responsible for integrating signals from the brain and the muscles to control and coordinate voluntary and involuntary contraction of muscles and movement. Motor neuron degeneration or dysfunction has been implicated in severe and debilitating diseases such as spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), post-polio syndrome (PPS), and others. iPSC-derived motor neurons provide a convenient, consistent, reliable, and physiologically relevant source of cell lines to model diseases and to test novel therapies.