IRS1 and liver cancer: Three cell lines that originate from different mammalians (mouse myoblast cell line (C2C12), human liver cancer cell line (HepG2), and rat hepatoma cell line (Fao)) that are used widely for insulin research were selected to examine the phosphorylation changes of key biomolecules including Insulin receptor (INSR), Insulin receptor substrate 1 (IRS1), Extracellular signal-regulated kinase 1/2 (ERK1/2), Akt phosphorylated at S473 (pAkt(S473)), Akt phosphorylated at T308 (pAkt(T308)), p70 Ribosomal S6 kinase (p70S6K), GSK3β, and Forkhead box protein O1 (FoxO1).