To determine the role of NOTCH1 (a hub gene of PPI in somatic mutated genes) in the radiosensitivity of ESCC, we then knocked down its expression in ESCC cells (KYSE-150 and TE-1) by shRNA and utilized qPCR to verify the knockdown efficiency (Figure 5A). Here, NOTCH1 is linked to esophageal squamous cell carcinoma.