皮膚幹細胞

Let me address your problem one by one.
點解皮膚細胞可以用黎做幹細胞???
幹細胞is a very general term, it is to describ the cell containing re-generative power, that is to keep on proliferating the same. On 皮膚細胞, research also find Skin Stem cells, besides, there are also heart stem cells, blood stem cells, muscle stem cells, eye stem cells.........etc
There are different types of stem cells at different " differentiation " level. For example, skin stem cells are " more 已分化 " then embryonic stem. Eg. embryonic stem can differentiate into skin stem cells but not vice versa. Skin stem can only proliferate themselves and differentiate into skin cells only!

皮膚細胞明明係已分化,有function既細胞.....點解依然可以做幹細胞(未分化既細胞)???
Look at the answer in above.