SHH and mucopolysaccharidosis type 2: In a zebrafish model of mucopolysaccharidosis type II, perturbations of glycosaminoglycan catabolism were associated with aberrant distribution and signaling of morphogens, such as sonic hedgehog (Shh), dysregulation of the Shh and Wnt/β‐catenin signaling, and aberrant heart development and atrioventricular valve formation (Costa et al, 2017).