Serpin B7
Encoded by the SERPINB7 gene on chromosome 18, Serpin B7 is an intracellular clade B serpin with unusually high expression in keratinocytes, placenta, kidney and heart. Its precise target protease remains uncertain, yet the protein accumulates in the cytoplasm of differentiating squamous epithelium and is markedly upregulated in several squamous cell carcinomas, prompting its evaluation as a diagnostic and prognostic tissue marker. Studies link Serpin B7 to protection against proteotoxic stress and to regulation of cell survival in the epidermis. Loss-of-function variants have been associated with Nagashima-type palmoplantar keratoderma in Japanese families, underscoring its role in skin homeostasis and barrier integrity.
