Therefore, we speculated that UBE2V2 in lung cancer increased PCNA activity in the S phase, which would induce the transfer of damaged DNA from the replication mechanism to the trans‐injury synthesis pathway mediated by the RAD5‐UBE2V2‐UBC13 protein and eventually lead to lung cancer cells developing resistance to a variety of chemotherapeutic drugs. The gene discussed is UBE2V2; the disease is lung cancer.