In view of these observations, particularly paying attention to the roles of MuSK in Wnts/MuSK CRD non-canonical and canonical pathways, we assayed the serum samples from 43 nAChR antibody-negative MG patients using the recombinant proteins expressed in HEK 293F cells as antigens [65]. The gene discussed is CHRNA4; the disease is myasthenia gravis.