Little Ryan Ferguson of East Kilbride, was diagnosed with the condition in August 2011.
After he was diagnosed with acute myeloid leukemia, doctors said Ryan's only hope of survival was a bone marrow transplant.
In October 2011, Strathclyde Fire & Rescue joined the appeal for a bone marrow donation to help save the little boy's life.
Firefighters helped arrange a donor recruitment event and almost 1500 people gave samples.
Ryan finally received a bone marrow transplant at Glasgow's Yorkhill Hospital for Sick Children last January.
His dad, Stuart, said: "When we found out Ryan needed a transplant we hoped to get around 200 people to agree to be tested, but thanks to Strathclyde Fire & Rescue we got nearly 1500.
"Their help has meant everything to our family and we will always be grateful.
"Firefighters save lives and this is another way of doing just that."
Today fire bosses are calling for more potential bone marrow donors to sign up to the national register.
Strathclyde Fire & Rescue has again teamed up with the lifesaving leukemia charity The Anthony Nolan Trust.
Deputy Assistant Chief Officer Ally Boyle, said: "Anyone who meets Ryan can see the incredible impact being a donor has.
"He is a fun-loving, energetic four-year-old who is full of life - that would not be possible if people hadn't registered to be a lifesaver.
"Both the Fire Service and Anthony Nolan pride ourselves on our determination and ability to save lives and this partnership has made a huge difference - people are alive today because of it."
To find out more about joining the bone marrow register, visit the web page www.nthonynolan.org/ What-you-can-do.aspx