In the MCTD patients, the TNF-α serum levels were generally higher, but we did not observe differences between individual miR-143 rs353299 and miR-143 rs353298 genotypes (p = 0.57, ε2 = 0.02; p = 0.36, ε2 = 0.04; respectively). Here, TNF is linked to mixed connective tissue disease.