TWIST2 and ossification of the posterior longitudinal ligament of the spine: The results showed that lnc-KRT18-1, TSPEAR, CLIC2, ANKRD33B, TWIST2, C19orf73, TBX19, TWIST2, LOC101926975, and ABLIM1 had the highest number of interactions, which revealed the vital roles of these genes in the pathogenesis of OPLL (Figure 5).