Although loss-of-function variations in PCSK9 confer protection against cardiovascular heart disease [27–29] and pharmacological inhibition of PCSK9 appears to be effective in reducing the risk of MACE also in subjects with diabetes [30], the value of PCSK9 level measurements as a prognostic biomarker for MACE prediction remains a field fraught with uncertainty. The gene discussed is PCSK9; the disease is diabetes mellitus.