Statistical analysis showed that TP53 and RB1 mutation frequencies were significantly higher in cases with tumor stages III and IV than in those with tumor stages I and II, while the mutation frequencies of TAF1, LRP1B, SDHA, CBFB, BRIP1, and SMAD4 were significantly higher in cases with tumor stages I and II than in those with tumor stages III and IV (Fig. 7B). Here, SMAD4 is linked to neoplasm.