['Over- or underexpression of certain Eph receptors has been associated with tumorigenesis of some types of cancer. EphB1 is a member of receptor tyrosine kinases of the EphB subfamily involved in the development, progress and prognosis of colorectal cancers. The expression levels of EphB1 in colon cancer cell lines and human colorectal carcinoma specimens were determined and association of EphB1 expression with clinicopathological parameters was analyzed.', 'Quantitative real-time reverse transcription polymerase chain reaction and immunohistochemistry were used.', 'The EphB1 transcript is expressed in all colon cancer cell lines tested. However, there is marked variability in the expression of the EphB1 transcripts and proteins among colorectal carcinoma specimens. Reduced expression of EphB1 in colorectal cancers more often occurred in poorly differentiated and mucinous adenocarcinomas than in well- and moderately differentiated adenocarcinomas. Further, cancer cells with a low level of EphB1 protein showed more invasive power.'] Is ephB1 underexpressed in poorly differentiated colorectal cancers?