ATF6 and metastatic melanoma: Moreover, we found that ATF6 expression was increased significantly in metastatic melanomas after screening a panel of primary melanoma and metastatic melanoma tissues for the expression of ATF6 in a serial tissue microarray (same as PTEN and Entpd5 and IGF1R) by immunohistochemical staining (p< 0.001, Figure 7I).