TRIM21 and osteosarcoma: In agreement with these reports, we found that TRIM21 overexpression significantly inhibited the protein expression of SGLT2, but not the mRNA expression of SGLT2 in osteosarcoma cells (Fig. 2d and Supplementary Fig. 1a), and TRIM21 silencing significantly induced the protein expression of SGLT2 in osteosarcoma cells (Fig. 2e).