GPBAR1 and cancer: However, not only CDCA is a very weak agonist for GPBAR1 and transactivation of EGFR by GPBAR1 has been reported only in cancer cells, i.e., in cells that express very high levels of EGFR, but, surprisingly, TCA (i.e., the physiological ligand of GPBAR1) failed to elicit mature IL-1β secretion or pro-IL-1β and NLRP3 assembly even when administered to pre-activated macrophages (40).