Neck anatomy has long terrified me. Way back when I was a grad student, my lab studied the organization and development of the hindbrain, which was relatively tidy and segmental; my research was studying the organization and development of the spinal cord, which was also tidy and segmental. The cervical region, though, was complicated territory. It's a kind of transitional zone between two simple patterns, and all kinds of elaborate nuclei and new cell types and structural organizations flowered there. I drew a line at the fifth spinal segment and said I'm not even going to look further anteriorly…good thing, too, or I'd probably still be trying to finish my degree.
Fortunately, Matsuoka et al. were braver than I was and they have applied some new molecular techniques to sort out some of the details of how the neck and shoulder are assembled. This is a developmental study of how the muscles and bones of the shoulder girdle and neck are derived, and what they've identified is 1) a fairly simple rule for part of the organization, 2) an explanation for some human pathologies, and 3) some interesting observations about evolution. It is very cool to find a paper that ties together molecular genetics, development, paleontology, and medicine together so inseparably.