CCR1 and colorectal cancer: We analysed by quantitative RT-PCR (real time-quantitative reverse transcription polymerase chain reaction) the expression levels of human CCL5 and its receptors CCR1, CCR3 and CCR5 on surgical resection pieces of human primary colon tumors, of paired hepatic and pulmonary colorectal cancer metastases and of corresponding healthy tissues collected from the same patients.