JUN and neoplasm: Recently, several studies have reported exciting findings, including the regulation of the physical interaction between IRF4 and its binding partners, the formation of ternary complexes through overexpression of BATF or c-Jun, and the regulation of the amount of IRF4 or BATF, which are essential for rescuing exhaustion and improving anti-tumor potency in tumor-specific CAR-T cells (25, 89, 90).