Major knowledge gaps were noted among participants in some of the test questions, including ‘Eating too much sugar and other sweet foods is a cause of diabetes’, ‘Usual cause of diabetes is lack of effective insulin in the body’, ‘Diabetes can be cured’, ‘Tight elastic hose or socks are not bad for diabetics’, and ‘Diabetic diet consists mostly of special foods’. This evidence concerns the gene INS and diabetes mellitus.