Tree shrews used to be considered close relatives to primates but modern DNA tests show that it isn’t so.
Currently tree shrews are classified in their own order Scandentia. Tree shrews are not really shrews, or rodents, or primates as people thought at various times.
For various reasons tree shrews are often used in medical research and their DNA has been one sequenced relatively early for research purposes.
Northern treeshrew (Tupaia belangeri).
Tree shrew (Tupaia belangeri) Genome Browser Gateway.