A New York police officer who was diagnosed with leukaemia which doctors believe was brought on by his efforts on September 11th was saved by a transatlantic stem cell donor who joined the donor register thirty years ago. Greg Holgerson, 42, was told his leukaemia could be linked to his involvement in the recovery efforts after the September 11th attacks on the World Trade Centre. Greg was present at the site on the evening of the attack to secure the area and help with the recovery. ‘Everyone there was covered in dust and debris. It looked like it was snowing, it…