ADP ribosylation factor like GTPase 6 interacting protein 6 is a protein that in the humans is encoded by the ARL6IP6 gene. ARL6IP6 (ADP-ribosylation-like factor 6 interacting protein 6), also known as PFAAP1 (phosphonoformate immuno-associated protein 1), is a 226 amino acid multi-pass membrane protein that belongs to the ARL6IP6 family and is encoded by a gene that maps to human chromosome 2q23.3. A 2q23.3 novel microdeletion involving seven genes, including ARL6IP6, is linked to a proposed 2q23q24 microdeletion syndrome. Additional chromosome 2q deletions, which also include ARL6IP6, are linked to autism, developmental delays and communication impairment. As the second largest human chromosome, chromosome 2 makes up approximately 8% of the human genome and contains 237 million bases encoding over 1,400 genes. Chromosome 2 contains a probable vestigial second centromere, as well as vestigial telomeres, which gives credence to the hypothesis that human chromosome 2 formed as a result of an ancient fusion of two ancestral chromosomes, which are stillpresent in modern day apes.