KRT7 and malignant colon neoplasm: Previous studies have shown that CK 7 negativity with CK 20 positivity has the greatest predilection for colorectal cancers.14 However, it has also been demonstrated that upto 17% of colon cancers are positive for CK 7 whereas upto 19% of these tumors are negative for CK 20.15 Hence although CK7+/CK20- pattern in metastatic biopsy may point towards gastric cancer primary yet its absence does not rule out the possibility of primary colorectal neoplasm.15