Inclusion Criteria:  Have consented to be part of the NIHR BioResource; Are aged 18 years and above; Have given written informed consent to participate in the GENBIO study; Are carriers or non-carriers of the candidate functional genetic variant(s) of interest.  Exclusion Criteria:  Have a chronic disease, including cardiovascular diseases, autoimmune diseases and cancer.  Additional exclusion criteria to be applied at the discretion/opinion of the CI/collaborator, based on the population of available volunteers for recall and the genetic variant of interest (e.g. allele frequency):  Have a biological first-degree relatives (parents, brothers, sisters or children) who are suffering or have suffered from a disease/condition in the opinion of the CI/collaborator that, from a genetic standpoint, may affect the study validity; Are current regular smokers. Regular ex-smokers are suitable if they stopped smoking >10 years ago (regular defined as 1 pack year in both instances); Have ≥3 alcoholic drinks per day; Have a diagnosis of hypertension, or history of consistently high blood pressure readings, e.g. >140/90 mmHg; Have a diagnosis of hypercholesterolemia, or history of consistently high cholesterol levels, e.g. total cholesterol level >6 mmol/l; Are obese (i.e. BMI >30); Are unwilling to fast and not to consume products containing alcohol or caffeine 12 hours prior to procedures.