The BTB (broad-complex, Tramtrack and Bric a brac) domain, also known as the POZ (Poxvirus and zinc finger) domain, is an N-terminal homodimerization domain that contains multiple copies of kelch repeats and or C2H2-type zinc fingers. Proteins that contain BTB domains are thought to be involved in transcriptional regulation via control of chromatin structure and function. BTBD17 (BTB POZ domain-containing protein 17), also known as BTBD17A, galectin-3-binding protein-like or LGALS3BPL, is a 478 amino acid protein that contains one BTB (POZ) domain and a BACK (BTB Kelch associated) domain. The gene encoding BTBD17 maps to human chromosome 17, which comprises over 2.5% of the human genome and encodes over 1,200 genes. Two key tumor suppressor genes are associated with chromosome 17, namely, p53 and BRCA1. Malfunction or loss of p53 expression is associated with malignant cell growth and Li-Fraumeni syndrome.