Since the serum from B19 infected patients with MCTD or SLE recognized the B19-NS1-induced cleavage of 70 kDa U1-snRNP, however, it could suggest the association between B19-NS1 induced cleavage of 70 kDa U1-snRNP by B19-NS1 and autoimmunity. Here, LSM2 is linked to mixed connective tissue disease.