UI-R-EP0 is a subtracted cDNA library constructed according to Bonaldo, Lennon and Soares, Genome Research, 6:791-806, 1996. First strand cDNA synthesis was primed with an oligo-dT primer containing a Not I site. Double stranded cDNA was ligated to an EcoR I adaptor, digested with Not I, and cloned directionally into pT7T3-Pac vector. The oligonucleotide used to prime the synthesis of first-strand cDNA contains a library tag sequence that is located between the Not I site and the (dT)18 tail. The sequence tags for this library are: distal colon, GAAGTGCTCC; osteoblast, AAGATATCAA; cell line R3327 5A, GGACTAGATC; cell line R3327 5P, CACGTGAGAT; duodenum, TGTGGTTCAT; prostate, CCAGG.