CD44 and neoplasm: A previous study also demonstrated that HAS3 overexpression markedly promotes filamentous actin aggregation in neuronal protrusions.37 The HA protein, which is generated by HAS3, significantly induces CD44 + neuroblastoma cell differentiation.23 However, the CD44‐ neuroblastoma cells escape melatonin‐induced HA‐mediated cell differentiation; they can then cause tumor formation.21, 22 These findings suggest that inducing HAS3 expression may be useful as a novel strategy for neuroblastoma cell differentiation therapy.