In a phase I trial on NSCLC patients, Ad-CCL21-DC increased the number of CD8+ T cells by an average of 3.4 times by intra-tumoral injection in over half of the patients.512 Tumor immunosuppression, particularly immune resistance against tumor-specific T cells, is associated with dysregulated expression of tumor immune checkpoint proteins. This evidence concerns the gene CD8A and non-small cell lung carcinoma.