AGRN and myasthenia gravis: Reportedly, the MMP-3 level is high in the serum samples from a proportion of MG patients (Helgeland et al., 2011; Romi et al., 2012), suggesting that the NMJ might be affected by the pathogenic mechanisms as the result of the dysfunction of agrin that is brought about non-immunologically by high MMP-3 level in addition to the immune response to agrin (Luckman et al., 2011; Chan et al., 2020).