stem cells from the bones of children

[zenba]

you won't like this answer. the human cells most closely related to stem cells, and most easily and often harvested, are the cells of the foreskin.

foreskins are harvested to make `beauty` products and do as you say, replace damaged tissue in adults.

there are underground cloning facilities as well where cells and tissues are harvested. this isn't something you can find proof of online though.