FHIT and neoplasm: Hao et al (2000) examined aberrant crypt foci (ACF), adenomas, primary colorectal carcinomas (CRCs) and metastatic lesions for Fhit protein expression by immunohistochemistry. In all, 44% of carcinomas showed marked loss or absence of expression and the fraction of tumours with reduced expression increased with decreasing differentiation and in tumours with metastases (62 vs 38% in tumours without metastases); 12 out of 13 metastatic lesions showed reduced expression.