Tables V and VII lists the 21 allelic variants identified in IRS-1. The coding region and short intron-exon borders of IRS-2 were investigated by automated sequencing in 12 CRC cell lines and 33 primary CRCs. Tables VI and VII summarize the 18 distinct allelic variants identified in IRS-2. Some of the detected IRS-1 and IRS-2 variants are common polymorphisms also found in the general population (Table VII) (17,20–30) and are described in public databases. This evidence concerns the gene IRS1 and colorectal carcinoma.