Importantly, expression of this protein was also found on tumor cells in these tumors [22], and this expression correlates with malignancy grade in a human melanoma progression series: whereas PLXND1 is abundantly expressed in both invasive primary and disseminated melanomas, both in the vasculature and in tumor cells, its expression was absent in benign melanocytic lesions and melanomas in situ, except for expression on macrophages and fibroblasts [33]. Here, PLXND1 is linked to melanoma.