Fig. 3From: The origin of p40-negative and CDX2-positive primary squamous cell carcinoma of the stomach: case reportImmunohistochemistry of the tumor specimen (× 20). Immunohistochemistry of the resected tissue specimen was positive for cytokeratin (CK) 5/6, and caudal-type homeobox protein 2 (CDX2), slightly positive for CK20, and negative for p63, p40, and CK7Back to article page