Erector pili muscle and hair growth

I read both papers. Thanks. Doctors in my industry have had discussions at the meetings about the role of the arrector pili muscle in the growth cycle of the human hair and we frankly don’t know its value. When we transplant hairs the arrector pili muscle is detached in the grafts and the hair grows nevertheless. From my recent readings, the stem cells around the erector pili muscle may be responsible for the start of a new anagen cycle. More research is now being done on this very important set of stem cells