Secretoglobins (also called lipophilins or mammaglobins) are small secreted proteins of endocrine-responsive organs and mucosal epithelia that form multimeric complexes and correlate with the development of various human cancers. Lipophilin A and Lipophilin B are orthologs of prostatein (estramustine-binding protein), the major secretory glycoprotein of the rat ventral prostate gland. Lipophilin A, also designated LIPA, LPHA and secretoglobin, family 1D, member 1 (SCGB1D1), is a component of a heterodimeric molecule present in human tears. Lipophilin B, also designated LIPB, LPHB and secretoglobin, family 1D, member 2 (SCGB1D2), mRNA can be overexpressed in breast tumors and shows a high degree of correlation with the mRNA expression profile of mammaglobin. Histological detection in breast tissue of Mammaglobin A, also designated MGB1 and secretoglobin, family 2A, member 2 (SCGB2A2) and Mammaglobin B (also designated MGB2, lipophilin C, LPHC, UGB3 and SCGB2A2) is a reliable diagnostic marker for breast tumors.
