INS and diabetes mellitus: Animal and in vitro model systems have indicated that arsenic exposure can potentially increase the risk of diabetes through its effects on the inhibition of insulin-dependent glucose uptake (Walton et al. 2004) and insulin signaling (Paul et al. 2007), impairment of insulin secretion and transcription in pancreatic beta cells (Diaz-Villasenor et al. 2006), and modification of the expression of genes involved in insulin resistance (Diaz-Villasenor et al. 2007).