HEAT repeats form rod-like helical structures that are involved in intracellular transport. HEATR7B2 (HEAT repeat-containing protein 7B2) is a 1,585 amino acid protein that contains fifteen HEAT repeats. Existing as two alternatively spliced isoforms, the gene encoding HEATR7B2 maps to human chromosome 5p13.1 and mouse chromosome 15 A1. Chromosome 5 contains 181 million base pairs and comprises nearly 6% of the human genome. Cockayne syndrome is associated with chromosome 5 through the ERCC8 gene and familial adenomatous polyposis via the adenomatous polyposis coli (APC) tumor suppressor gene. Treacher Collins syndrome is also chromosome 5-associated and is caused by insertions or deletions within the TCOF1 gene. Deletion of the p arm of chromosome 5 leads to Cri du chat syndrome, while deletion of the q arm or of chromosome 5 altogether is common in therapy-related acute myelogenous leukemias and myelodysplastic syndrome.