T cell (TC: CD3D, IL7R), natural killer cell (NK: NCAM1), B cell (BC: CD79A, MS4A1), monocyte (MC: CD14, LYZ), and dendritic cell (DC: CLEC10A, CD1C) were annotated based on the expression of canonical lineage markers and other genes specifically upregulated in each cluster (Figure2A; Figure S1C,D, Supporting Information), as our previous paper pertaining to uveitis diseases.[26, 27, 28] We used samples from six patients with BU and samples from six HCs as two groups (referred to as the BU group and HC group) for comparative analysis. The gene discussed is MS4A1; the disease is uveitis.