AGR2 and infection: To further confirm that AGR2 is essential for cancer tumorigenesis, we next investigated the effects of overexpressing AGR2 in non-tumorigenic HBECs using lentivirus-mediated infection with either empty vector (HBEC-EV) (Figure 4A, top panels) or AGR2 containing vector (HBEC-AGR2) (Figure 4A, bottom panels).