It is an outbred strain.

Outbred homozygous nude (Foxn1^nu/Foxn1^nu) mice are the standard in vivo model for drug efficacy testing in oncology.

Nude mice are athymic and hairless as a result of the recessive “nu” mutation.

Although T cell precursors exist, their development is blocked because of the absence of a thymus, resulting in an immunodeficiency that permits transplantation of tumour cell xenografts hence, these outbred nude mice act as immunodeficient tumour transplant hosts.

Homozygous females are poor breeders and fail to lactate.

Heterozygous males and females breed well and have normal immune function.

Homozygous pups can be identified at as young as 24 hours by their lack of whiskers or poorly developed, crinkled whiskers.