CD19 and neoplasm: Based on marker genes of immune cells, six major categories of immune cells were identified in the tumor microenvironment, including B cells (CD19+), CD4 + T cells (CD3e + CD4 + ), CD8 + T cells (CD3e + CD8a + ), myeloid cells (CD11b + ), NK cells (NK1.1 + ), and a small group of double-negative CD3 + T cells (CD3e + CD4-CD8a-) (Fig. 5b, and Supplementary Fig. 12b, c).