JUNB and cancer: Interestingly, co-IP and Western blot analysis detected the interaction of JunB, but not c-Jun, with ATXN3 in transiently transfected HEK293T cells (Supplemental Figure 6A and Supplemental Table 1), implying a possibility that ATXN3 may enhance AP-1–mediated PD-L1 gene transcription in cancer cells through JunB stabilization.