The applied anti-tumor drugs induce apoptosis by an intrinsic pathway.32, 33 GJs arewell-known to facilitate intrinsic apoptosis via ‘death signal’transmission among cancer cells.9, 34, 35 In thepresent study, Cx32 expression did not enhance streptonigrin-induced apoptosis inhuman CaCx cells, even though it suppressed apoptosis after 2APB inhibited the GJ. Here, GJB1 is linked to cancer.