SHMT2 and osteosarcoma: In CRC and osteosarcoma, SIRT5 desuccinylates mitochondrial serine hydroxymethyltransferase (SHMT2) at K280 to increase its enzymatic activity, driving serine catabolism and promoting tumor proliferation.159 These results suggested that protein succinylation is used by cancer cells to adapt to metabolic status for rapid growth.