[1] 在皮肤中，胆固醇硫酸酯（当然是由胆固醇产生的）主要位于表皮层，并在其中起着重要的调节作用。在这里，基底细胞（图4.1）开始分化并迁移到活表皮层的外层，在那里胆固醇硫酸酯含量达到最大值。然后死亡的表皮层又会被分解，产生所谓的“表皮胆固醇硫酸酯循环”。皮肤中的胆固醇硫酸酯是保持皮肤各层贴合在一起，并能够相互滑动的关键。这种层与层之间的平滑运动可使皮肤具有很大的弹性。所以，随着胆固醇硫酸酯水平的降低，皮肤的弹性也会降低。

[2] Paraskevi Gkogkolou, Markus Böhm,“Advanced Glycation End Products: Key Players in Skin Aging?”, Dermato-Endocrinology 4, no. 3 (2012): 259-270, doi: 10.4161/derm.22028, PMID: 23467327。

[3] Douglas R. Seals的文章很好地描述了血管系统随着年龄的增长而衰退的情况，“Edward F. Adolph Distinguished Lecture: The Remarkable Anti-Aging Effects of Aerobic Exercise on Systemic Arteries”, Journal of Applied Physiology 117, no. 5 (2014): 425-439, doi: 10.1152/japplphysiol.00362.2014, PMID: 24855137。

[3] Douglas R. Seals的文章很好地描述了血管系统随着年龄的增长而衰退的情况，“Edward F. Adolph Distinguished Lecture: The Remarkable Anti-Aging Effects of Aerobic Exercise on Systemic Arteries”, Journal of Applied Physiology 117, no. 5 (2014): 425-439, doi: 10.1152/japplphysiol.00362.2014, PMID: 24855137。

[4] 想要了解更多关于雄激素悖论的信息，可参阅以下这篇综述：Shigeki Inui, Satoshi Itami,“Androgen Actions on the Human Hair Follicle: Perspectives”, Experimental Dermatology 22, no. 3 (2013): 168-171, doi: 10.1111/exd.12024, PMID: 23016593。

[5] 更多关于将头发干细胞作为一种潜在的治疗脱发的方法的内容可参阅一篇可读性较强的、非技术性的概要，“New Way to Activate Stem Cells to Make Hair Grow”, ScienceDaily ，发布时间2017年8月14日，www.sciencedaily.com/releases/2017/08/170814134816.htm。

[6] 更多关于棕榈酰和其他肽类的信息，可参阅Roanne R. Jones, Valeria Castelletto, Che J. Connon, Ian W. Hamley,“Collagen Stimulating Effect of Peptide Amphiphile C16–KTTKS on Human Fibroblasts”, Molecular Pharmaceutics 10, no. 3 (2013): 1063-1069, doi: 10.1021/mp300549d, PMID: 23320752；相关临床试验可参阅L. R. Robinson, N. C. Fitzgerald, D. G. Doughty, N. C. Dawes, C. A. Berge, D. L. Bissett,“Topical Palmitoyl Pentapeptide Provides Improvement in Photoaged Human Skin”, International Journal of Cosmetic Science 27, no. 3 (2005): 155-160, doi: 10.1111/j.1467-2494.2005.00261.x, PMID: 18492182。

[7] 更多关于NO的疗法可参阅James Q. Del Rosso, Leon H. Kurcik,“Spotlight on the Use of Nitric Oxide in Dermatology: What Is It? What Does It Do? Can It Become an Important Addition to the Therapeutic Armamentarium for Skin Disease?”, Journal of Drugs in Dermatology 16, no. 1 (2017): s4-10, PMID: 28095537。

[8] 想要了解更多关于头发移植实验的信息，原始论文可参阅Mingqing Lei, Linus J. Schuma-cher, Yung-Chin Lai, Weng Tao Juan, et al,“Self-Organization Process in Newborn Skin Organoid Formation Inspires Strategy to Restore Hair Regeneration of Adult Cells”, Proceedings of the National Academy of Sciences U.S.A. 114, no. 34 (2017): E7101-7110, doi: 10.1073/pnas.1700475114, PMID: 28798065。在南加利福尼亚大学的新闻稿中，有一个简短的、非技术性的概要（https://stemcell.keck.usc.edu/usc-stem-cell-scientists-obtain-how-to-guide-for-producing-hair-follicles/)。

[9] 该公司的名称是OneSkin (https://www.oneskin.co/blogs/reference-lab/oneskin-launches-molclock-the-first-skin-specific-molecular-clock-to-determine-the-biological-age-of-human-skin)；创立该公司的科学家们只发表了一篇过程相关论文，即使用表观遗传时钟来确定皮肤样本的生理年龄：Mariana Boroni, Alessandra Zonari, Carolina Reis de Oliveira, Kallie Alkatib, Edgar Andres Ochoa Cruz, Lear E. Brace, Juliana Lott de Carvalho,“Highly Accurate Skin-Specific Methylome Analysis Algorithm as a Platform to Screen and Validate Therapeutics for Healthy Aging”, Clinical Epigenetics 12 (2020): article no. 105, doi.org/10.1186/s13148-02000899-1。该公司网站明确表示，人体临床试验正在进行中。

[10] 关于鉴定 IRF4 基因作用的相关研究，可参阅Christian Praetorius, Christine Grill, Simon N. Stacey, Alexander M. Metcalf, et al,“A Polymorphism in IRF4 Affects Human Pigmentation through a Tyrosinase-Dependent MITF/TFAP2A Pathway”, Cell 155, no. 5 (2013): 1022-1033, doi: 10.1016/j.cell.2013.10.022, PMID: 24267888。SNPedia网站对其他将这种基因与各种癌症联系起来的研究进行了详尽的综述：https://www.snpedia.com/index.php/Rs12203592，这也是一个搜索特定基因信息的好网站，就像NCBI网站（https://www.ncbi.nlm.nih.gov/gene）一样。

[11] 如果你想要深入探讨，可参阅以下这篇很好的综述，Sylvie Ricard-Blum,“The Collagen Family”, Cold Spring Harbor Perspectives in Biology 3, no. 1 (2011): a004978, doi: 10.1101/cshperspect.a004978。 7gc+U0toD6id9v1RvALFYLhKcRcD+yx0zpgpW6YEyz0/SgpHHN91Spk+w8eP31WW