CCDC91 (Coiled-Coil Domain Containing 91), a protein-coding gene, is associated with diseases such as ossification of the posterior longitudinal ligament of the spine and diffuse idiopathic skeletal hyperostosis (https://www.genecards.org/cgi-bin/carddisp.pl?gene=CCDC91 accessed on 2 January 2022). This evidence concerns the gene CCDC91 and diffuse idiopathic skeletal hyperostosis.