She didn't start the fire: Mammary duct epithelial cells suppress adipocyte thermogenesis.

Male and female mice display highly divergent responses to cold-induced thermogenic beiging of subcutaneous adipose tissues. Recently in Nature, Patel et al. showed that mammary duct epithelial cells respond to cold-induced sympathetic activity, triggering the secretion of lipocalin 2 (LCN2) to inhibit thermogenic differentiation of adjacent mammary adipocytes.