JUN and neoplasm: For example, after glutamine deprivation in the culture medium, the renal cancer cell lines and bladder cancer cell lines up-regulated the expression of PD-L1 in tumor cells by activating the EGFR/ERK/C-Jun pathway, which is an important immunosuppressive molecule that binds to the PD-1 receptor on the surface of immune cells, inhibiting the anti-tumor immune response.