NECTIN4 and gallbladder carcinoma: For the understanding of the function of Nectin-4 in cancer, Zhang et al. reported that Nectin-4 regulates Rac-1 activity by activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway to mediate cell proliferation and migration in gallbladder carcinoma [13].