CD44 and rhabdomyosarcoma: By contrast, a study performed by Saxon et al., in 12 pediatric rhabdomyosarcoma tumor-derived cells (five alveolars, six embryonal, and one botryoid subtype) reported no association between the expression of ECM proteins (laminin, fibronectin, thrombospondin, tenascin) and CD44 with metastatic events at clinical presentation (163).