examined the expression of STAT5A and related prolactin receptor (PRLR) in normal and abnormal breast epithelial tissues and found that STAT5A is overexpressed in over 80% of normal cell nuclei with minimally detected PRLR, whereas the reverse was true for STAT5A and PRLR in breast carcinomas [44]. The gene discussed is STAT5A; the disease is breast carcinoma.