<Tr> <Th> Structure name </Th> <Th> Structure diameter </Th> </Tr> <Tr> <Td> Cajal bodies </Td> <Td> 0.2--2.0 μm </Td> <Td> </Td> </Tr> <Tr> <Td> Clastosomes </Td> <Td> 0.2 - 0.5 μm </Td> <Td> </Td> </Tr> <Tr> <Td> PIKA </Td> <Td> 5 μm </Td> <Td> </Td> </Tr>

Where is a nucleus found in a cell