In order to clarify whether the correlation between TMPRSS2 and immune infiltration is due to the recruitment of immune cells by TMPRSS2, or whether immune cells themselves express TMPRSS2, we used single-cell sequencing data from patients with NSCLC in the TSICH database to study the expression of TMPRSS2 in different cells (Figure 5B) and found that TMPRSS2 was mainly expressed in epithelial cells and malignant cells, but was hardly expressed in immune cells. This evidence concerns the gene TMPRSS2 and non-small cell lung carcinoma.