Two molecular function GO terms significant for both the OZALC-NAG and SAGE studies group genes related to retinoid binding (Table 3), and exhibit a hierarchical relationship among them, GO:0001972 being the most specific and the term GO:0005501 the most general. Both studies share 4 significant genes (Figure S3) encoding the cellular retinoic acid binding proteins 1 (CRABP1 - chr 15q24), and 2 (CRABP2 - chr. 1q21.3); insulin-like growth (IGF2R - chr 6q26); and the complex of genes UDP glucuronosyltransferase 1 family, polypeptide A (UGT1A1/3/4/6/7/8/9/10), which are associated with the metabolism of nicotine [34]. Due to the physical overlap on the chromosome of this complex of genes, we employed UGT1A4, as a representative of the entire complex, eliminating the other members from the database of terms.
