Canine, Equine, Human, Mink, Cynomolgus Monkey, Ferret, Dolphin, Rabbit, Feline, and Bat CXCL14 (C-X-C motif chemokine ligand 14), also known as BRAK (breast and kidney–expressed chemokine), is a homeostatic chemokine belonging to the CXC chemokine family that plays a role in immune surveillance, epithelial defense, and tissue homeostasis. In these species—including dogs (Canis lupus familiaris), horses (Equus caballus), humans (Homo sapiens), mink (Neovison vison), cynomolgus monkeys (Macaca fascicularis), ferrets (Mustela putorius furo), dolphins (e.g., Tursiops truncatus), rabbits (Oryctolagus cuniculus), cats (Felis catus), and bats—the CXCL14 protein is identical at the amino acid level, demonstrating remarkable evolutionary conservation across diverse mammalian lineages and indicating that its biological function has been strongly preserved. CXCL14 is broadly expressed in epithelial tissues, skin, and mucosal surfaces, where it is produced by epithelial cells, fibroblasts, and other stromal cells under homeostatic conditions. It contributes to the recruitment and positioning of immune cells such as dendritic cells, monocytes, and natural killer (NK) cells, supporting early immune surveillance and maintenance of tissue integrity at barrier sites. In many of these species, CXCL14 is particularly relevant in skin and mucosal immunity, helping regulate responses to environmental pathogens and microbial colonization. Because CXCL14 is structurally identical across these mammals and participates in epithelial immune defense and innate immune regulation, it is studied in comparative immunology, mucosal immunity, cancer biology, and host–pathogen interaction research, providing insight into conserved chemokine-mediated mechanisms of immune surveillance across mammalian species.