A large number of studies in the last three decades have identified only a handful of biological features in the evolution of human premalignant breast lesions (PBL). They have shown that PBL have a positive growth balance, which may be driven/regulated by oestrogen receptor, erbB-2, and p53. There is marked genetic diversity in PBL, and use of newer technologies such as SAGE, DNA microarrays, and high-throughput proteomics will significantly improve our understanding of evolution of PBL over the next decade.