Spherical bodies.
D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008854:Microscopy, Electron; D009368:Neoplasm Transplantation; D012190:Retroviridae / Q000302:isolation & purification*; D012509:Sarcoma / Q000382:microbiology / Q000648:ultrastructure*; D014183:Transplantation, Heterologous