Among the immune cells that were highly and positively correlated with CASP8, those highly expressed in the patients with AF were CD8 T cells, CD4 T cells, regulatory T cells (Tregs), myeloid-derived suppressor cell (MDSC), macrophages, plasmacytoid dendritic cells, NK cells, and NK T cells. The gene discussed is CD8A; the disease is atrial fibrillation.