Here we report the use of our established human in vitro NMJ BioMEMs system (Santhanam et al., 2018; Guo et al., 2020b) to dose SKM with a commercially available antibody against nAChR to simulate the three proposed pathogenic mechanisms of MG – blocking, modulation, and binding (Figure 1). The gene discussed is CHRNA4; the disease is myasthenia gravis.