INS and type 2 diabetes mellitus: Interestingly, it was found that overexpression of protein tyrosine phosphatase-1B in tissue cells reduces the activity of protein tyrosine kinase, which prevents the insulin receptor from binding to insulin, which in turn causes insulin resistance (IR) and ultimately leads to T2DM, whereas cinnamaldehyde inhibits the activity of protein tyrosine phosphatase-1B, which can help to treat or prevent T2DM (Saifudin et al., 2013).