NFKB1 and esophageal squamous cell carcinoma: We also found that TNFR1 overexpression activated its mediated MAPK and NF-κB pathways in ESCC cells, as indicated by the enhanced phosphorylation of ERK, p38, and p65 without an alteration in their total protein levels, while TNFR1 knockdown exhibited the opposite results (Figure 4E).