Cell‐Type‐Specific Expression of Human Endogenous Retroviruses and Epigenetic Regulators in Human Peripheral Blood

cells to allow direct comparison across cell types. HERV transcripts were predominantly detected in leukocytes, whereas reticulocytes and platelets exhibited minimal expression. Within leukocytes, granulocytes displayed significantly higher HERV expression than PBMCs, despite comparable levels of SETDB1 and TRIM28. These findings demonstrate that HERV transcription in peripheral blood is highly cell-type-specific and largely attributable to granulocytes, providing a framework for interpreting whole-blood HERV measurements and highlighting the importance of accounting for blood cell composition in translational studies.