RNASE8 is a ribonuclease A family member uniquely expressed in placental tissue 1, encoded by a gene located on chromosome 14 alongside other RNase A superfamily genes 1. The protein exhibits low ribonucleolytic activity 1 and does not display the antiviral or antibacterial activities characteristic of other RNase family members 1. However, RNASE8 is proposed to contribute to innate immune defense mechanisms 2, with functional annotations suggesting roles in antifungal responses and defense against both gram-positive and gram-negative bacteria [GO annotations]. The gene has undergone rapid evolutionary changes, including disulfide bond reshuffling through cysteine substitutions in great apes approximately 7-13 million years ago 3, and exhibits elevated non-silent mutation rates with orthologous deactivation in multiple primate species, suggesting specialized placental function 1. Recent evidence indicates RNASE8 expression is regulated by miRNA-455-3p and is upregulated in ocular surface inflammation associated with Stevens-Johnson syndrome, implicating it in epithelial immune responses 4. The tissue-specific expression and rapid evolutionary divergence suggest RNASE8 performs a unique physiological role distinct from other RNase family members.