We first demonstrated that GUSB‐H351Q has a remarkable tumor‐promoting function both in vitro and in vivo and further demonstrated that GUSB‐H351Q increased the N‐glycosylation level of PD‐L1 through STT3B, which indicated that this type of mutation may play an indispensable role in tumor immune evasion. This evidence concerns the gene CD274 and neoplasm.