HOXD13 and non-small cell lung carcinoma: To further investigate whether higher concentrations of sPD-L1, sPD-1, and sCTLA-4 reflect the exhaustion status of T cell–mediated antitumor immunity, we next examined the relation between gene expression in peripheral CD8+ T cells and the concentration of each soluble immune factor with the use of pretreated blood samples from 40 patients with NSCLC from cohort B (Figure 1B) (27).