We examined expression patterns of imc-415 gene in mammary gland and in HC11 mammary epithelial cells in culture. mRNA levels of imc-415 gene were higher at pregnancy and involution stages of mouse mammary gland compared with lactation period. Expression of imc-415 gene was induced with serum starvation or treatment with Fas monoclonal antibody in HC11 mammary epithelial cells in culture.