CD8A and colorectal carcinoma: DCA, a key mediator of “hostile bile” effects, directly impairs CD8+ T cell function by dysregulating plasma membrane Ca2+ ATPase (PMCA)-mediated calcium efflux, disrupting intracellular Ca2+ homeostasis and blunting nuclear factor of activated T cells (NFAT)2 signaling—critical for effector cytokine production—thereby accelerating CRC progression (239, 240).