PDIA3 and spondyloepimetaphyseal dysplasia, Strudwick type: Our results are of great interest for orthopedic research, as alterations in FN1 or in the FN1-triggered activation of integrins, both of which we assume to depend on extracellular ERp57 activity, are associated with skeletal diseases such as OA or spondylometaphyseal dysplasia (SMD) with corner fractures.16