title: Developmental biology. Why thumbs are up.
authors.forename: G R
authors.initials: GR
authors.lastname: Martin
mesh_terms: D000818:Animals; D004475:Ectoderm / Q000502:physiology; D047108:Embryonic Development; D004627:Embryonic Induction; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005121:Extremities / Q000196:embryology*; D006801:Humans; D015398:Signal Transduction