KRT7 and neoplasm: Allison et al. [18] immunohistochemically analyzed a series of 8 primary and metastatic angiosarcoma involving the gastrointestinal tract and found that tumor cells were immunoreactive for cytokeratins AE1/AE3 (7/8), cytokeratin 7 (2/8), Cam5.2/cytokeratin 8 (5/8), and cytokeratin 19 (5/8).