GJA1 and hepatocellular carcinoma: In addition, internally perfused Cx43-expressing oocyte pairs were insensitive to pHi [64], and Cx43-expressing Novikoff hepatoma cells were insensitive to pHi = 6.1, as long as [Ca2+]i was kept to resting levels with BAPTA in the patch pipettes (Figure 1) [31].