CD14 and systemic sclerosis: The fact that in this study mtDNA copy number disturbance was demonstrated only in CD14+ monocytes, while in whole blood there was no difference in mtDNA copy number between SSc and controls, allows considering mtDNA copy number in CD14+ monocytes as a potential indicator of mitochondrial dysfunction of monocytes in SSc and confirms the important role of CD14+ monocytes in pathogenesis of SSc.