PAX7 and rhabdomyosarcoma: Although rhabdomyoblasts are a useful clue that suggests rhabdomyosarcoma, it is not totally specific [51]. By immunohistochemistry, the tumor expresses desmin, myogenin, and myoD1. It is important to note that alveolar rhabdomyosarcoma can express focally neuroendocrine markers and cytokeratins, which might cause confusion. Molecular tests for PAX3-FOX01 or PAX7-FOX01 gene fusions are essential to confirm the diagnosis of alveolar rhabdomyosarcoma [51].