Interestingly, PTC patients with PD-1+CD39-CD103+ CD8+T cells were enriched in immune cells and had a high expression of inhibitory immune checkpoints and chemokines (Figure 6, Table 4), which is similar with the phenotype of anaplastic thyroid carcinoma-like PTC (54). The gene discussed is PDCD1; the disease is thyroid gland undifferentiated (anaplastic) carcinoma.