I’ve been on the Anthony Nolan donor register for over a decade. I joined after an argument: a straight girl friend had joined and was urging me to do the same.

“It’s really really hard for them to find matches for marrow: 1000s need a transfusion but can’t have one because there just aren’t enough people on the register,” she urged.

“I can’t. I’m gay,“ I said. “They won’t want mine.”

She snapped back that I was talking nonsense and I should phone them.

As a child, I longed to give blood and always went with my mum when she donated. It seemed to me the mark of mature engagement in wider society, the very definition of Civilised. I was very disappointed when I found I couldn’t give blood and presumed that the same restrictions would apply to bone marrow.

To my surprise, Anthony Nolan seemed delighted to hear from me and quickly sent me a kit to take to tissue type me. I was registered as a potential donor. I was shocked to hear how hard it is for them to find a match, and that there are millions of tissue types, as opposed to blood donor types.

It’s so easy to register: you can fill in the form online and they send you a simple saliva test that you do yourself and freepost back. It really couldn’t be easier. It’s not much of a hassle when you think how much of a lifesaver it could be – how much more inconvenient to be a nine year old with lymphoma who is running out of survival options? A mother who desperately needs a transfusion in order to live to see her children reach maturity?

I’d urge everyone who is fit and healthy to register with the charity. They are particularly looking for men between the ages of 18 and 30 as these are most likely to be physically larger and fit, making them the best potential group of donors.

Trying to find a correct bone marrow match for someone with a blood cancer, such as leukemia, is like looking for the proverbial needle in a haystack, but the more of us sign up, the more there will be to find. The more lives will be saved. Simple.