Men in Hoddesdon are being asked to give just 20 minutes of their time to help two sisters boost the donor list.
Sisters Rebecca and Rachel Hall, aged 17 and 22, are running a campaign to get more bone marrow donors on the national list.
Rebecca, of Stanstead Abbotts, said: “It only takes 15 to 20 minutes to sign up and it’s not as hard as people think.”
Young men are the group most needed on the list, as they are more likely to be used by transplant doctors.
The sisters began their campaign on behalf of a relative in Cumbria who has been diagnosed with terminal cancer.
Their distant cousin, Alice Pyne, 15, has written a wish list of things she wants to achieve before she dies and one of these is to inspire more people to sign up to the Anthony Nolan stem cell transplant register.
The girls all met at a registration event organised by Alice’s family to try to find a bone marrow match for her.
Rebecca said: “A match was found, but by that time Alice was too ill to have the transplant. If that match had been found sooner, she might have been able to have her transplant.
“We’ve been following her story and kept in touch with the family but I felt like I still wanted to do something to help her with the wishes on her bucket list as nothing else can be done, so that no other family goes through what her family have had to go through.”