STAT3 and esophageal squamous cell carcinoma: Since knockdown and overexpression CHRNA7 in two ESCC cells reduced or enhanced phosphorylation of JAK2 (p-JAK2) and STAT3 (p-STAT3), respectively, without affecting the total levels of these factors (Supplementary Fig. 2e), we examined the correlation between CHRNA7 and CIC-associated markers in a GEO database (GSE47404) and found that CHRNA7 expression is highly associated with SOX2 (r = 0.6812, P < 0.001) and NANOG (r = 0.2689, P = 0.023) (Supplementary Fig. 2f).