Hair Growth Control by Innate Immunocytes: Perifollicular Macrophages Revisited

The document from April 1, 2019, examines the role of perifollicular macrophages (pfMACs) in hair follicle biology, particularly their involvement in the regulation of hair growth cycles and their potential as a target for treating hair growth disorders. It highlights the interaction between pfMACs and hair follicle epithelial stem cells through Wnt signaling, which is crucial for the transition between hair cycle phases. The paper also discusses the contribution of pfMACs to hair cycle-associated processes such as angiogenesis and immune privilege, as well as their role in hair-related immunopathologies like alopecia areata. The authors suggest that further research into pfMACs could lead to novel treatments for hair growth disorders and provide insights into broader biological processes. However, the document does not involve a clinical trial or specify the number of people studied, as it is a viewpoint on pfMACs' role in hair biology rather than empirical research.