Common melanocytic nevi are ubiquitous lesions which in some cases constitute a risk factor for the development of melanoma. To date, despite long term research there are no known molecular hallmarks for nevus development. We have observed that common acquired nevi excised from the same individual share remarkable similarity in their microscopic appearance and in the immunohistochemical expression of E-cadherin. Based on these observations, we hypothesize that all melanocytes are genetically similar in the same individual and changes predisposing to neoplasia are a global melanocytic event characteristic for each person and propose a microgenomics/proteomics approach to test this hypothesis.