C-peptide is seen

Insulin * Insulin is synthesized in the rough endoplasmic reticulum of the B cells * The gene for insulin is located on the sho arm of chromosome 11 in humans. * Normally, 90-97% of the product released from the B cells is insulin along with equimolar amounts of C peptide. * C peptide can be measured by radioimmunoassay, it is an index of B cell function in patients receiving exogenous insulin. Ref:- Ganong's Review of Medical Physiology 25th ed; pg num:- 431