As summarized above, the altered gene expression for MRPs such as, DAP3, MRPS6, MRPS18A, MRPS18B, and MRPS23 has been detected in highly proliferative and aggressive forms of breast cancers (40, 45, 46, 48, 50, 60); however, their steady-state protein expressions have not been studied in relation to neither OXPHOS subunit nor the mitochondrial translation component expressions in the majority of these studies. Here, MRPS23 is linked to breast cancer.