Though cleft lip and palate are relatively uncommon in CFNS patients relative to other craniofacial features, a recent genome-wide association study suggested that the EFNB1 locus may also be relevant to non-syndromic cleft lip with or without cleft palate, which underscores the importance of this pathway in normal development as well as in X-linked CFNS [71]. The gene discussed is EFNB1; the disease is cleft lip.