MS4A1 and cancer: B-lineage-related target antigens (CD19, MS4A1, CD22, TNFRSF17, CD38, SLAMF7, and TNFRSF8) not only exist in B lineage-derived normal or malignant tumor cells but are also expressed in other immune cell types (CD22/CD38/SLAMF7-expressing ASDC, CD38-expressing proliferating T lymphocytes, and SLAMF7-expressing cDC1) and non-immune cell types (CD38-expressing cardiac fibroblasts, SDC1-expressing AT1/AT2/basal cells, and CD22/CD38/SDC1/TNFRSF8-expressing pancreatic acinar/ductal cells) at a certain frequency.