title: Repetin
text: # Repetin
  
  Repetin is an extracellular matrix protein expressed in the epidermis. In humans it is encoded by the RPTN gene. Repetin is part of the S100 fused-type protein family and contains an EF hand structural domain.
  
  It functions in the cornified cell envelope formation. It is a multifunctional epidermal matrix protein. RPTN reversibly binds calcium.
  
  RPTN is 5,634 bases long. It starts 152,126,071 base pairs from pter. It ends 152,131,704 base pairs from pter. It has a minus strand orientation.
  
  RPTN is one of the genes that differ between present-day humans and Neanderthals. RPTN helps protect skin cells, and since the Neanderthals were missing this protein, the Neanderthals were better adapted to the cold, but less so to disease.
  
  