We're looking down at a section about 650,000 nucleotides from the tip of the short arm of human Chromosome 11. This is equal to about 1/2 of one percent of the entire chromosome and about 1/5,000th of the human genome. In this region there are 28 genes, and more than 500 transposons, or jumping genes. We first encounter a cluster of five small genes, averaging about 1,500 nucleotides in length. These encode components of hemoglobin, the oxygen carrying molecule of the blood. Next we encounter two small genes that encode olfactory receptors, common features of Chromosome 11. These are followed by an "intergenic region" of 183,000 nucleotides, lacking any known genes. Scattered throughout this region are numerous "simple repeats" composed of multiple copies of a repeated sequence of 2-50 nucleotides, and more than 100 transposons that litter the intergenic region. The intergenic region is followed by two adjacent ubiquilin genes, which are involved in key cell processes, from replication to "programmed" death. These are followed by a cluster of genes encoding olfactory receptors (LOC), which receive stimuli in the nose to allow us to detect smells. Next follows a cluster of four genes in the tripartite motif (TRIM) family. TRIM proteins contain three motifs, or structures, through which they bind to DNA to regulate gene activity. Our tour ends with another cluster of nine olfactory receptor genes (LOC). Chromosome 11 contains about 40% the estimated 1,000 genes for olfactory receptors in the human genome. There is such a concentration of receptor genes at the tip of Chromosome 11 that this whole region could be called an olfactory supercluster, in which the beta globin, ubiquilin, and TRIM clusters are embedded.