NDP and dysplasia: NDP (Norrin Cystine Knot Growth Factor NDP) encodes a secreted protein with a cysteine knot motif that activates the Wnt/beta-catenin signalling pathway and has been associated with dysplasia in dogs (Joyce et al., 2021), whereas EFHC2 (EF-Hand Domain Containing 2) is associated with fear recognition and harm avoidance in humans (Blaya et al., 2009).