KRT79 (keratin 79) is a type II cytokeratin with dual roles in skin and liver physiology. In skin, KRT79 identifies a specialized population of migratory epithelial cells that initiates hair canal morphogenesis during both embryonic development and adult hair regeneration 1. These K79+ cells stream outward from hair germs prior to lumen formation and subsequently line the hair follicle infundibulum, a multilayered domain maintained by stem cell-derived progeny 1. KRT79 expression is regulated by the transcription factor Gata6, which maintains upper hair follicle integrity; loss of Gata6 causes hair canal dilation independent of KRT79 expression changes 2. Beyond its structural role, KRT79 is also expressed in hepatocytes, where it functions as a PPARA target gene 3. Hepatic KRT79 expression is undetectable in normal liver but dramatically increases in response to PPARA agonists and metabolic stress (fasting, high-fat diet), with expression completely abolished in Ppara-null mice 3. This stress-responsive regulation suggests KRT79 may serve as a diagnostic biomarker for liver disease 3. Clinical relevance extends to eosinophilic esophagitis, where KRT79 appears dysregulated in disease transcriptomes 4, and keratoconus, where altered RNA editing affects KRT79 expression 5.