SDHB and cancer: SDH is a tricarboxylic acid (TCA) cycle enzyme complex consisting of four protein subunits (succinate dehydrogenase A [SDHA], succinate dehydrogenase B [SDHB], succinate dehydrogenase C [SDHC], and succinate dehydrogenase D [SDHD]); it is involved in the mitochondrial electron transport chain and is required for cellular energy metabolism, and altered activity of the SDH is linked with a subset of human cancers in which cell metabolism changes [8, 9].