Editorial Volume 9, Issue 12 pp 2453—2454

Figure 1. Intraductal injection. (A) The human breast consists of multiple ductolobular stems that transport the milk produced during lactation in terminal ductolobular units through the breast ducts that surface at the nipple. (B) Mammary ducts are bilayered epithelial structures. The inner luminal cells are responsible for milk production and the outer myoepithelial/basal cells contract upon oxytocin release to excrete the milk. (C) The murine mammary gland is composed of a branching ductal network localized in the mammary fat pad. The mouse mammary gland has one efferent duct. (D) In mice, the nipple can be cannulated with a short, blunt-ended needle (left picture) for ID injection with ablative reagents (indicated in blue; right picture).