PELI1 and squamous cell carcinoma: As expected, PELI1 knockdown significantly promoted the accumulation of NIK proteins and thus enhanced the activation of the IR‐induced noncanonical NF‐κB signaling pathway in TE‐1, ECA‐109, SCC‐9 and SiHa squamous carcinoma cells, resulting in enhanced p52 and RelB entry into the nucleus (Fig. 5C,D, Fig. S4D).