IGF1R and esophageal squamous cell carcinoma: Interestingly, IGF1R was elevated in ESCC compared with EAC patients (p = 0.0048) within the GO2 cohort (Figure S5D), and we saw no significant effect of IGF1R expression on OS in the EAC population (Figure S5E), suggesting that IGF1R may be a poor prognostic factor selectively in squamous carcinoma.