s. Marked increases were observed in the glycolytic capacity and glycolytic rate by circMAT2B‐overexpressing in hypoxic Huh7 and SMMC7721 cells, whereas both were reduced by circMAT2B knockdown in hypoxic HepG2 and Focus cells (Fig. 3D,E and Supporting Fig. S5C,D). Moreover, the mitochondrial function of oxidative phosphorylation was also influenced by circMAT2B levels, as reflected by the alteration in oxygen consumption and respiratory capacity. CircMAT2B overexpression under hypoxia led to an overtly decreased basal OCR and significantly lower maximum OCR compared with controls. Instead, under hypoxia, circMAT2B knockdown resulted in elevated OCR at both basal and maximal levels (Figs 3F,G and Supporting Fig. S5E,F).