B2M and renal cell carcinoma: As the key upstream enzyme of the TCA cycle, Pyruvate kinase M2 (PKM2) was overexpressed in RCC tumor samples (Figure S3C, Supporting Information), suggesting potential correlations of metabolic disruption with the whole TCA cycle.[18] To further assess the influence of time and concentrations of αKG supplementation on B2M expression, we conducted western blot analysis and observed significantly elevated B2M expression in Renca cells treated with 5 mm αKG for 4 days (Figure S3D,E, Supporting Information).