TLDR Trichoepitheliomas and some basal cell carcinomas likely come from hair follicle stem cells.
The study suggested that trichoepitheliomas and some basal cell carcinomas originated from hair follicle stem cells, particularly from the bulge area of the outer root sheath. This was supported by the expression of cytokeratin 15 (K15), identified using an anti-CD8 monoclonal antibody, in 100% of trichoepitheliomas and 27% of basal cell carcinomas. Other skin tumors, such as squamous cell carcinomas, were K15-negative, while tumors of follicular derivation like proliferating trichilemmal cysts were K15-positive. The findings indicated a link between these tumors and hair follicle stem cells.
318 citations
,
October 1998 in “The Journal of Cell Biology” Keratin 17 is important for skin development and may help define skin cell types.
638 citations
,
October 1997 in “Nature” 96 citations
,
December 1995 in “Journal of Investigative Dermatology” 122 citations
,
July 1994 in “Journal of Investigative Dermatology” 
253 citations
,
March 1994 in “Developmental dynamics” Apoptosis is essential for human skin development and forming a functional epidermis.
61 citations
,
August 1993 in “PubMed” Basal cell epithelioma likely starts from the hair follicle's outer root sheath.
128 citations
,
February 1992 in “British Journal of Dermatology” Basal cell carcinomas likely originate from hair follicle cells or stem cells.
47 citations
,
April 1978 in “Journal of Cutaneous Pathology” Basal cell epithelioma resembles fetal hair follicles, not adult or fetal skin.
7 citations
,
November 2022 in “Communications biology” Keratin injections can promote hair growth by affecting hair-forming cells and tissue development.
19 citations
,
February 2013 in “Archives of Dermatological Research” 10 citations
,
October 2000 in “PubMed” E6/E7 oncogenes in hair follicles cause continuous hair growth by skipping the resting phase.
94 citations
,
February 1994 in “The journal of investigative dermatology/Journal of investigative dermatology” EGF makes hair follicles grow longer but stops hair production.
128 citations
,
February 1992 in “British Journal of Dermatology” Basal cell carcinomas likely originate from hair follicle cells or stem cells.
198 citations
,
November 1989 in “The Journal of Cell Biology” Keratin K14 expression varies between hair follicles and epidermis, affecting cell differentiation.
135 citations
,
November 1987 in “Differentiation” Outer root sheath cells consistently express certain keratins influenced by their environment.
