The gene for prolactin-inducible protein (PIP), uniquely expressed in exocrine organs, maps to chromosome 7.

The hormonally responsive prolactin-inducible protein (PIP) gene is expressed in benign and malignant breast tumor tissues and in such normal exocrine organs as sweat, salivary, and lacrimal glands. In this communication we report the regional chromosome localization of the PIP gene locus to chromosome 7 by Southern hybridization to DNA from human-hamster somatic cell hybrids, and to 7q32-36 by in situ hybridization.