NTN1 and cleft palate: Wang [38] et al. revealed a significant correlation between GREM1 polymorphism rs1258763 and the risk of nonsyndromic orofacial clefts, and Viena CS [39] found that interaction between NTN1 and GREM1 may be associated with the pathogenesis of nonsyndromic cleft lip with or without cleft palate.