FAS and X-linked Charcot-Marie-Tooth disease type 1: In our study, both the ER stress marker BiP and CHOP, along with the pro-apoptotic marker Fas, were mostly elevated in the presence of the T55I mutant suggesting that under stress conditions intracellularly retained Cx32 mutants may exacerbate ER stress upon neuroinflammation, leading to the development of CNS phenotypes in CMT1X patients.