HERPUD1 and cancer: Our findings reveal that HERPUD1 is highly expressed in BC compared to NBT and promotes aggressiveness in MDA-MB-231 cells, providing a mechanistic link between cancer and ER stress pathways [2, 49, 57], and highlighting CK2 as a potential regulatory target for therapeutic intervention in highly metastatic TNBC tumoral cells by modulating HERPUD1 function.