Clefts of the oral-facial region usually occur in early fetal development and can affect the lip, the soft palate and the hard palate. Cleft lip (with or without cleft palate) is a genetically complex birth defect that occurs in approximately one in every 750-1,000 live births. This is one of the most common birth defects and is multifactorial, with both genetic and environmental causes. Cleft lip- and palate-associated transmembrane protein 1 (CLPTM1) belongs to a family of cleft lip and palate transmembrane proteins. This family also contains cisplatin resistance-related protein (CRR9), which is involved in CDDP-induced apoptosis. CLPTM1L (cleft lip and palate transmembrane protein 1-like protein), also known as CRR9p (cisplatin resistance-related protein 9) is a 538 amino acid multi-pass membrane protein that belongs to the CLPTM1 family and, when overexpressed, enhances cisplatin-mediated apoptosis. CLPTM1L exists as two alternatively spliced isoforms encoded by a gene that maps to human chromosome 5p15.33.