There are many different examples of mouse mutants in which the caudal neural tube is abnormal but the phenotype differs from spina bifida. In many cases, these are described as spinal neural tube defects [100–103]. Apart from the 3 mutants with only spina bifida (Fgfr1, Shp2, and Gcm1) which have 2 neural tubes with one notochord, 2 other mutants with spinal defect but no spina bifida share the same predicament. These are the EphA2 null mouse  and PAK4 null mouse . Another abnormal spinal neural tube phenotype is a wavy spinal neural tube that occurs in the WASP null mouse and the Vinculin null mouse [102, 103]. Vinculin is a large protein that binds multiple cytoskeletal proteins, actin, α-actinin, talin, paxillin, VASP, ponsin, vinexin, and protein kinase C (PKC) which have been suggested to be the adhesion scaffold that connects early adhesion sites to actin-driven protrusive machinery in enabling motility .