The objective of this protocol is to further elucidate the genetic mutations that drive melanocytic nevi (benign melanocytic neoplasms, moles). This will be performed by whole genome, whole exome, or targeted sequencing of de-identified specimens.

Herein, the investigators plan to isolate DNA from de-identified skin biopsy specimens and blood samples:

1. From melanocytic nevi collected by skin biopsy (a shave or punch biopsy). A part of the tissue will be submitted for routine diagnostic dermatopathology and investigational histomorphologic and immunohistochemical analysis.
2. From corresponding normal tissue (blood). DNA isolated from blood will be used as a normal control when analyzing sequencing data to identify somatic mutations in lesional tissue.

Inclusion criteria:

• Male or female subjects that are 18 years or older
• Subjects with melanocytic nevi\

Exclusion criteria:

• Patients less than 18 years of age
• Patients without melanocytic nevi
• Patients with a bleeding disorder or are taking anticoagulation medication

Subjects seen in UC Davis dermatology clinic diagnosed as having melanocytic nevi will be recruited from the clinic during their routine visit. Subjects identified in clinic will be approached after their clinic visit.