SDHB and plasma cell myeloma: Overexpression of SDH subunits, in contrast, has been rarely described in cancer although elevated SDHA expression levels have been observed in metastatic uveal melanoma (37), advanced ovarian cancer (38), and multiple myeloma (39), in which they are linked to enhanced OXPHOS capacity, increased expression of proteins that shuttle electrons between different complexes of the ETC, augmented levels of key TCA enzymes, enhanced ATP yield, and amplified metabolic plasticity (37, 38).