The article from science magazine above discusses the stem cells that are found in the bulge of the hair follicle (in the upper third of the follicle) and that these cells can generate new hairs to populate the bald head. It reminded me of a classic article by Jung-Chul Kim et.al. when he performed partial graft implantation to determine if two hairs could be produced by transplanting two different anatomic parts of a single hair follicle. As stem cells are in the bulge of the upper hair follicle and also in the bulb at the bottom of the hair follicle, he had hoped that two full terminal hairs would rise from the fragments of the original hair as the stem cells in each fragment was capable of generating a hair. In a limited study, Kim removed the upper 2/3rds of the hair follicles from his donor area and transplanted it into his leg. He also removed the lower 1/3rd of the follicle to include the bulb and transplanted that into his leg as well. He showed that the upper 2/3rds of the hair follicle can generate a full hair follicle and the lower 1/3rd can also generate a hair follicle; however, the growth rate of the upper 2/3rd was only 40% and the hair was finer in character (which has much less cosmetic value) and the lower 1/3rd of the follicle growth rate was 27%. By adding these two growth rates together (27% + 40%) the total growth rate was 67%. This study was performed on 67 human hair follicles, i.e. a feasibility study and the conclusion is that the process didn’t work as hoped. So when he cut the hair follicles into two, he ended up with less than the full cosmetic value of the original hair. I wish it worked! Many people have replicated his experiment with similar results.