Our results indicate that calcification is also part of zebrafish IVDD and associated with genes involved in bone formation and remodeling, as we detected calcification in nearly 80% of aged spines and in younger zebrafish showing misalignments; severe calcification was observed in zebrafish carrying mutations in sp7 and cathepsin K. Disc calcification is observed in other zebrafish mutants linked to collagenopathies, such as col1a1 +/−29, col1a1b−/−29, bmp1a−/−29, crtap−/−30, p3h1−/−30, and plod2−/−62. This evidence concerns the gene CTSK and collagenopathy.