On the shoulders of giants: A historical perspective of unique experimental methods in mammary gland research

► The mouse mammary gland is an organ of complex developmental control. ► The unique development of the mammary gland enables distinctive experimental techniques. ► Transplantation has been key in unraveling molecular and cellular effectors of development. ► Complex cell culture systems established the role of extracellular proteins in differentiation. ► Virus-based gene expression provides novel means for genetically investigating development.