I had the privilege of working closely with Dave during the early part of his long career in the Blood Service. I always look back on this period as one of excitement and challenge. His inspiration was to know the research questions to be asked as much as focusing his brilliant mind on the seeking of answers. He was modest and and unassuming, some would say the epitome of a 'mad scientist', never actively seeking awards or recognition whilst being surprised when they came seeking him. Dave was a friend and mentor, someone who was easy to talk to and who always made time for you. Truly irreplaceable, a huge loss. Peter Holt