In the tumor purity condition, the down-regulation of KLRB1 expression was significantly correlated with changes in the expression levels of immune cell markers such as CD3E, CD2, CD3D, CCR7, CD8A, TBX21, CD8B, CTLA4, CD19, HLA-DPB1, PDCD1, HLA-DRA, HLA-DPA1, CD79A, CCR8, STAT4, FOXP3, IFNG, CD86, HAVCR2, STAT5A, MS4A4A, LAG3, IL10, GZMB, GATA3, CD1C, IL17A, CSF1R, ITGAX, IL21, HLA-DQB1, VSIG4, CD68, STAT1, CD163, STAT5B, ITGAM, KIR3DL2, KIR2DL3, KIR2DS4, KIR2DL4, KIR3DL1, CEACAM8, KIR2DL1, TNF, TGFB1, PTGS2, IRF5, STAT6, CCL2, IL13, and KIR3DL3 (Table 4 and Fig. 14). The gene discussed is CD19; the disease is neoplasm.