The mutation in Clb gene, which is required for EGFR internalization and lysosomal degradation, results in the inhibition of the ubiquitin‐mediated degradation and has been linked to gastrointestinal tumor formation.49 However, in our results, we identified that Cullin 4B (CUL4B), a member of E3 ubiquitin ligases, was overexpressed in drug‐resistant cell lines. The gene discussed is CUL4B; the disease is digestive system neoplasm.