Traceable author statements that are referred to in other papers

[jmcmurry]

"Slavotinek et al. [6] have reviewed the phenotypes associated with 2q24-2q31 and 2q31-33 deletions. The 2q31.1 region includes the HOXD cluster, one of four highly evolutionally conserved, homologous gene clusters coding for transcription factors with crucial roles in embryonic development. More specifically, the HOXD cluster has been implicated in limb formation [4, 7]."

This was a statement in passing and not the assertion of the enclosing paper. PMC4498842

However, we probably do want to capture this stuff but how? As a GO annotation?