A Guide to Studying Human Hair Follicle Cycling In Vivo

The document from 2016 serves as a guide for classifying human hair follicle (HF) cycle stages in vivo, which is essential for hair growth disorder diagnosis and hair research. It introduces a xenograft model using human scalp skin grafted onto mice to study human HF cycling and provides criteria for identifying HF stages, combining morphological and histochemical markers. The guide includes schematic drawings, micrographs, and recommendations for designing experiments, while noting the limitations of murine models due to interspecies differences. It calls for a standardized, accessible guide for human hair cycle staging, aiming to standardize research practices in the field.