RHD and rhabdomyosarcoma: To assess differences in nuclear characteristics between normal human myogenic cells and rhabdomyosarcoma (RMS) cells, cultured proliferating human myoblasts (MB), differentiated myotubes (MT) and cell culture models of RMS representing both PAX-FOXO fusion-negative (RD, SMS-CTR) and fusion-positive (RH30) subtypes had their nuclei visualized using DAPI staining (Figure 1A).