Metformin, a widely prescribed drug for treating type II diabetes, is one of the most extensively recognized metabolic modulators, with activating AMPK.32 Metformin showed inhibitory effect in various cancer cell lines and xenograft cancer models and sensitized chemotherapy drugs.33 Our recent study has demonstrated that metformin alone inhibited bladder tumour growth and increased the efficacy of gefitinib via activating AMPK.34 To determine the role of metabolic modulators, we observed that metformin inhibited PKM2 expression obviously (Figure 4A‐B). This evidence concerns the gene PKM and type 2 diabetes mellitus.