Cidea is an essential transcriptional coactivator regulating mammary gland secretion of milk lipids

Cidea is typically thought of as a lipid droplet–associated cytoplasmic protein in brown adipose tissue. Peng Li and colleagues now show that it is also in the nucleus, and in mammary gland epithelial cells it acts as an essential transcriptional coactivator of C/EBPβ to regulate the expression of genes involved in milk lipid secretion during lactation.