PIK3CA and esophageal squamous cell carcinoma: The results showed that high expression of p-PI3K (P = 0.018), high expression of Ki-67 (P = 0.002), nerve invasion (P = 0.002), and lymphatic metastasis (P < 0.001) were independent risk factors for ESCC patients; treatment (P = 0.002) was an independent protective factor in ESCC patients (Figure 8).