NDUFB6 and breast cancer: Eichelser et al. (2014) explored the expression of ci-miRNAs in blood sera of breast cancer patients using quantitative TaqMan MicroRNA assays; according to their findings, cell-free miRNAs- 101 and -373 can be used as breast cancer-specific markers, additionally, sera levels of exosomal (not cell-free) miR-373 are significantly higher in the TNBC subtype and in ER-/PR− breast cancer patients, thus, suggesting a correlation between miR-373 and negative receptor status [113].