ALK and melanoma: The pertinent negative markers include histiocytic markers (CD163, CD14, CD1a, langerin), FDC markers (CD21, CD23, CD35, clusterin, CXCL13), hematolymphoid markers (CD45, CD3, CD20, CD79a), vascular markers (CD31, CD34), melanoma markers (melanA, SOX10, HMB45, S100), and others (ALK, CD30).