STAT3 and colitis: Several studies have established that metformin can attenuate colitis in mice by suppressing nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) (Koh et al., 2014), Phosphorylated-Signal transducer and activator of transcription 3 (pSTAT3) (Lee et al., 2015), Jun N-terminal kinases (JNK) (Deng et al., 2018) and p38 mitogen-activated protein kinase (MAPK) activation (Di Fusco et al., 2018).