The Cancri system was an inhabited neutral planetary system.
In 2256, Cancri IV hosted peace negotiations between the Klingons and the Federation. (DIS: "Lethe")
In the Bayer designation system, "Cancri" is used in the names of stars in the constellation Cancer.
According to the revised edition of the Stellar Cartography: The Starfleet Reference Library ("History of the United Federation of Planets"), the Cancri system was located in the Beta Quadrant. Furthermore, the reference work identified the system as 81 Cancri.