There are multiple definitions:

1. quick response(English)

   • a graphical code to identify an item / message
   • GSM
   • Data exchange

2. quantized reduction(English)

   • reducing cohesin levels reveals a preferential binding of cohesin to pericentric regions over cohesin-associated regions (CAR) on chromosome arms. QR is a powerful tool to study other proteins/pathways with multiple functions in disorders such as Cornelia de Lange Syndrome and Roberts Syndrome
   • CAR
   • Genetics, Biochemistry
   • https://doi.org…cub.2010.04.018