CDKN2AIPNL (CDKN2A interacting protein N-terminal like) is a 116 amino acid protein that belongs to the CARF family. Existing as two alternatively spliced isoforms, CDKN2AIPNL is encoded by a gene that maps to human chromosome 5q31.1. Chromosome 5 contains 181 million base pairs and comprises nearly 6% of the human genome. Chromosome 5 is associated with Cockayne syndrome through the ERCC8 gene and familial adenomatous polyposis through 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.