Regarding tumor grade, sPD-1 levels were significantly higher in G1 tumors (45.90 pg/mL; IQR: 31.01–59.99) compared to G2–G3 tumors (36.30 pg/mL; IQR: 29.51–49.94; p = 0.016). This evidence concerns the gene HOXD13 and neoplasm.