MMEL1 and autoimmune disease: Currently, MMELI is associated with PBC [33], rheumatoid arthritis [34], and multiple sclerosis [35, 36] Although researches do not provide direct evidence implicating the association between MMEL1 and hypothyroidism, the involvement of MMEL1 in autoimmune diseases has been reported, and there exists the overlapping gene between PBC and autoimmune thyroid disease [37].