BCL2 and esophageal squamous cell carcinoma: Using a tumor xenograft mouse model and in vitro assays, it was also demonstrated that metformin can inhibit ESCC, possibly through inhibition of NF-κB activation, IGFR1, BCL-2, caspase-9, MMP-2 and MMP-9 downregulation, in addition to E-cadherin, BAX, BIM and caspase-3 upregulation [118,119,120].