NFKB1 and squamous cell carcinoma: The results showed that IR could significantly increase the accumulation of NIK protein, a master kinase of the noncanonical NF‐κB signaling pathway, in ESCC TE‐1 and ECA‐109 cells and in SCC‐9 and SiHa squamous carcinoma cells (Fig. 5A,B, Fig. S4C).