The HOXB3 (homeobox B3) gene, another candidate gene for non-syndromic cleft lip and palate, is a member of the HOX3 family (part of the HOXL subfamily) that has been shown to transcriptionally regulate the expression of JAG1 gene (Jagged Canonical Notch Ligand 1) in a synergistic manner during pharyngeal arch development [22]. Here, JAG1 is linked to cleft lip.