the girl was 4 at the time of treatment. How could they preserve the cord cells for 4 years? The fact that nothing is said about it makes me suspicious of this article.
iirc, the cells are frozen or suspended in a special solution indefinitely.
red blood cells can be stored for many years, at least 10
It is stored in liquid nitrogen.
Same way they store semen for artificial insemination which they have been doing with cows for many years.
BTW I have 3 G kids who have theirs stored. (Just in case since their other grandfather died of leukemia)