CD8A and neoplasm: We have observed a strong PD effect (6.6-fold increase in plasma l-arginine 16 h upon last dose, Figure 4B), which correlated with a reversal of the immunosuppression in the tumour microenvironment, as evidenced by decreased levels of Tregs (p = 0.0196), MDSCs (p = 0.0173) and neutrophils (p = 0.0284), as well as by a beneficial increase in the CD8+/Treg cell ratio (p = 0.0281, Figure 4C).