FGFR2 and Beare-Stevenson cutis gyrata syndrome: Consistent with this role for FGF signalling, a recent report analysing the spectrum of phenotypes for human syndromes generated by heterozygous constitutive activation of FGFR2 (Pfeiffer, Crouzon, and Beare-Stevenson syndromes) included an ectopic “caudal appendage” [56], suggesting conservation in humans of a mechanism that attenuates FGFR signalling for normal cessation of body axis elongation.