On the PCNA substrate, all the characteristic Raman peaks of glucose molecules were clearly identified and distinguished even at a low Mf of 0.1%, corresponding to a concentration of 5.6 mM (which agrees with the typical glucose concentration of 3–7 mM in the blood of healthy people as opposed to 10–20 mM in the blood of diabetes patients31. The gene discussed is PCNA; the disease is diabetes mellitus.