PLoS Biol. https://doi.org/10.1371/journal.pbio.3000528 (2019).

The naked mole rat (NM-R) is a eusocial, subterranean rodent species with a highly distinctive biology that includes extreme longevity and high resistance to age-related diseases and cancer. In PLOS Biology, Buffenstein and colleagues use single-cell RNA sequencing to characterize and compare the immune systems of NM-Rs and mice. In contrast to mice, which have a peripheral immune system numerically dominated by lymphocytes, NM-Rs instead have a myeloid-biased composition. More strikingly, NM-Rs apparently completely lack canonical NK cells and expression of molecules controlling NK cell functions. In particular, NM-Rs have a paucity of MHC class I molecules, with only 3 MHC I genes, as opposed to the 22 genes found in the mouse genome. This peculiar immune system might suggest that NM-Rs have undergone strong selection for antibacterial but not antiviral responses.