ACAN and spondyloepiphyseal dysplasia: For instance, the human ortholog of Acan, Col2a1, and Col11a1 are linked to spondyloepiphyseal dysplasia, osteoarthritis, disc degeneration (Nakane et al., 2011; Sahlman et al., 2001), and susceptibility to lumbar disc herniation (Mio et al., 2007).