VNN1 and spondyloarthropathy: In addition, Vanin-1 knockout corrected the increase in chondrogenesis in ank/ank (an animal model of spondyloarthropathy) bone marrow mesenchymal stromal cells (BMSCs) as well as the increase in chondrogenic transdifferentiation and calcification in ank/ank aortic smooth muscle cell explants (Johnson et al., 2008).