CPC Class C12Q

Non-human animals, and methods and compositions for making and using the same, are provided, wherein the non-human animals comprise a humanization of a Programmed cell death 1 (Pdcd1) gene. The non-human animals may be described, in some embodiments, as having a genetic modification to an endogenous Pdcd1 gene so that the non-human animals express a PD-1 polypeptide that includes a human portion and an endogenous portion (e.g., a non-human portion).

Methods and compositions for determining and/or monitoring the immune state of an individual are provided.