CLSTN1 and melanoma: In contrast, cadherin genes that are highly expressed in melanoma (Figure 1B and Figure 2A) tend to have low expression in normal skin in keratinocytes (e.g., calsyntenin-1 and cadherin-3), but their expression in endothelial cells, macrophages, and fibroblasts (e.g., protocadherin-1) may enable ‘wrong’ or ‘unphysiological’ cell–cell contacts promoting invasion and metastasis.