TRIM21 and brain neoplasm: TRIM21 depletion enhanced PFK activity, pyruvate kinase activity, lactate production (Supplementary Fig. 6c), cell proliferation (Supplementary Fig. 6d), and brain tumor growth in mice (Fig. 6f) and Ki-67 expression levels in human brain tumor tissues (Fig. 6g), and these effects were abrogated by reconstituted expression of WT rTRIM21 but not by that of its ligase-dead mutant.