GJA1 and neoplasm: It sensitised murine MLTC1 Leydig tumour cells to etoposide by increasing gap junction intercellular communication (GJIC) composed of connexin 43 (Cx43); this effect is related to the inhibition of protein kinase C (PKC)‐mediated Cx43 phosphorylation at serine 368 and subsequent increase in Cx43 membrane localization [52].